For those of you who don’t use it, the website Quora is an absolute goldmine for information on a wide variety of topics. It allows you to ask and answer questions by individuals who all use their real names, and who have to identify their area of expertise (their reason for knowing the answer.)
One of the questions asked was “What are some striking facts or figures about suicide?” My answer is the basis for this post. I identify a number of suicide facts and figures with citations. These may make useful additions to presentations that you do in the future.
We know that in the United States, about 50% of suicide deaths are by firearm (CDC, 2016). This accounts for the startling statistic that 60% of people who attempt suicide will die on their first attempt (Bostwick, et. al., 2016)
Of those that survive, 70% of those who live will never go on to have a second attempt, hopefully because they get the help that they need. About 23% will go on to attempt again (sometimes repeatedly) and live, while 7% will die on a future attempt. (Owens, Horrocks & House, 2002)
Gun owners in particular at much higher risk of suicide. We know that gun owners are 57 times more likely to die by suicide within 7 days of their purchase (likely because they purchased it specifically intent on suicide), and 7 times more likely within the first year as non-gun-owners. (Wintermule, et. al., 1999)
Depending on the type of gun and other variables, 85-98% of firearm suicide attempts will end in death, while only about 2% of overdoses will end in death. (Elnour & Harrison, 2008).
Women attempt suicide about 3 times as frequently as men do (Vijayakumar, 2015) but tend to die 3 times more frequently (Varnik, 2012) chiefly because of their use of more lethal methods like firearm and hanging, when compared to women who more commonly use overdose.
Suicide is most common in the middle ages, accounting for 54% of suicides in Canada (Statistics Canada, 2013) and 51% of suicides in the United States (CDC, 2011).
It’s been suggested that up to 90% of those who die by suicide have a diagnosable mental illness (Bertole & Fleischmann, 2002). Although this figure has been challenged because it is based on psychiatric autopsies (reviews with those left behind) that might be vulnerable to bias, it is common enough to be valuable.
Did I miss any suicide facts and figures that you’d like to see? Let me know and I’ll update the article. Thanks all!
Centers for Disease Control and Prevention (CDC). Web-based Injury Statistics Query and Reporting System (WISQARS) [Online]. (2013, 2011) National Center for Injury Prevention and Control, CDC (producer). Available from http://www.cdc.gov/injury/wisqars/index.html
Studies on the connection between religion and suicide have led to mixed results. Some studies indicated higher levels of suicidality, no relation or reduced risk. Many of the studies that indicated a relationship (either positive or negative), had mediators attached – such as that individuals who were more religious were less likely to attempt suicide as long as they lacked other social supports.
Religiosity and Suicide
Meta-reviews, large scale analyses of suicide risk have helped shed some evidence on the connection between religion and suicide.
Lawrence, Oquendo & Stanley (2016) noted that suicide and religion are both complex dimensions (e.g. suicide ideation versus attempts versus death, religious affiliation versus attendance.) Being part of a majority religious community was found to be a greater protective factor against suicide than a minority community, but that attending religious services was not as important as having social supports (whether religious or not.)
Norko et. al. (2017) noted that all major faith communities (including Islam, Hinduism, Judaism, Buddhism, and Christianity) have strong objections to suicide.
In Lawrence et. al. (2016) a sample of clinically depressed patients in a hospital setting were found to have a higher rate of suicidality if they identified a religious affiliation, the more they attended religious services, and the more they indicated religion was important.
Finally, Wu, Wang & Jia (2015), analyzing over 5000 participants across several large studies identified the three elements that are responsible for the protective factor of suicide: being of a western culture, being older, and living in a area with religious homogeneity.
Spirituality and Suicide
Spirituality can be examined through a lens different from organized religion. While religion may entail specific doctrine, spirituality instead examines one’s relationship with “self, others and ‘God’” (Mandhoui, et. al., 2016), in whatever form that takes.
Mandhoui et. al. (2016) surveyed individuals who were in hospital for suicide attempts. Those individuals lower in spirituality were more likely to attempt suicide at 18 months, with “value of life” tending to reduce the chance that someone re-attempts.
Amato, et. al. (2016) noted that spirituality can be integrated into suicide prevention programs such as case management, therapy and suicide assessment to determine the impact for that individual. They summarize the impact of spirituality by noting that “some individuals at high risk of suicide may find fellowship in an affirming community of faith; others may be helped by rituals that confer atonement or a state of exaltation; still others may learn, through mindfulness meditation, to suspend their inclination to judge themselves harshly.”
Specific Religions / Denominations and Suicide
Buddhism and Suicide
Buddhism has received some exploration in the scientific literature, especially in light of Buddhist monks who have self-immolated for political reasons, the most famous of whom was Thích Quảng Đức in 1963, but research on the exact suicide rate, especially when considered with other religions is lacking.
Lizardi & Gearing (2010) noted several elements that may decrease suicide in Buddhist individuals, including that the largest communities of Buddhists (Asian Americans and Pacific Islanders) have lower suicide rates than whites (who tend to belong to different religious communities) and a strong aversion to killing. In contrast, a belief in reincarnation and life-after-death may contribute to an increase in the suicide rate among specific individuals who adhere strongly to Buddhist traditions.
Catholicism / Protestantism and Suicide
Emile Durkheim in his 1897 work Suicide examined the suicide rates among Catholics and Protestants. He found that Catholics had much lower rates of suicide than Protestants and theorized that it was the result of social support provided in the Catholic community. Additional support was confirmed by Torgler & Schaltegger (2014) and Siegrist (1996) in a modern sample, who also found that church attendance reduced suicide.
Hinduism / Islam and Suicide
Ineichen (1998) examined a number of studies on Hinduism and Islam and consistently found that Muslims had much lower suicide rates than Hindus, focused on a variety of South Asian diaspora (such as individuals in the United Kingdom from other countries.)
Following up on this research, Thimmaiah et. al. (2016) explored a population of Muslims and Hindus in India and found that , while Muslims indicated more negative attitudes towards suicide which may help explain why they are less likely to attempt suicide.
Judaism and Suicide
Examining Jewish Israelis, Eliezer & Daniel (2012) found a rate of suicide lower in Jewish individuals than those who are Catholic or Protestant. Significantly, those with other risk factors for suicide (like veterans, immigrants or those who have experienced trauma) are at elevated at risk of suicide despite their religiosity.
After a review of the literature, it emerges that religious denominations and other factors can have an influence on suicide. Some religions have higher rates of suicide, and some have lower rates, which may be explained by the value system of those religions or the social support of those religions.
The suicide risk by religion, from highest to lowest is below:
Other religions with less well established data sets can be compared to each other, but not necessarily to other religions: Islam has a lower level of suicide than Hinduism, while Buddhism has a lower level of suicide than Native American spirituality.
Amato, J. J., Kayman, D. J., Lombardo, M., & Goldstein, M. F. (2016). Spirituality and religion: Neglected factors in preventing veteran suicide?. Pastoral Psychology, doi:10.1007/s11089-016-0747-8
Dyson, J., Cobb, M., Forman, D. (1997) The meaning of spirituality: a literature review. Journal of Advanced Nursing. 26(6). Retrieved on March 3, 2017 from http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2648.1997.00446.x/abstract doi: 10.1046/j.1365-2648.1997.00446.x
Durkheim, E. (1897). Le suicide: étude de sociologie. F. Alcan: Chicago, IL.
Eliezer, W., & Daniel, S. (2012). Suicide in Judaism with a Special Emphasis on Modern Israel. Religions, Vol 3, Iss 3, Pp 725-738 (2012), (3), 725. doi:10.3390/rel3030725
Ineichen, B. (1998). The influence of religion on the suicide rate: Islam and Hinduism compared. Mental Health, Religion & Culture, 1(1), 31.
Lawrence, R. E., Brent, D., Mann, J. J., Burke, A. K., Grunebaum, M. F., Galfalvy, H. C., & Oquendo, M. A. (2016). Religion as a risk factor for suicide attempt and suicide ideation among depressed patients. Journal Of Nervous And Mental Disease, 204(11), 845-850. doi:10.1097/NMD.0000000000000484
Lawrence, R. E., Oquendo, M. A., & Stanley, B. (2016). Religion and suicide risk: A systematic review. Archives Of Suicide Research, 20(1), 1-21. doi:10.1080/13811118.2015.1004494
Mandhouj, O., Perroud, N., Hasler, R., Younes, N., & Huguelet, P. (2016). Characteristics of spirituality and religion among suicide attempters. Journal Of Nervous And Mental Disease, 204(11), 861-867. doi:10.1097/NMD.0000000000000497
Norko, M. A., Freeman, D., Phillips, J., Hunter, W., Lewis, R., & Viswanathan, R. (2017). Can Religion Protect Against Suicide?. Journal Of Nervous & Mental Disease, 205(1), 9-14. doi:10.1097/NMD.0000000000000615
Siegrist, M. (1996). Church Attendance, Denomination, and Suicide Ideology. Journal Of Social Psychology, 136(5), 559-566.
Thimmaiah, R., Poreddi, V., Ramu, R., Selvi, S., & Math, S. (2016). Influence of Religion on Attitude Towards Suicide: An Indian Perspective. Journal Of Religion & Health, 55(6), 2039-2052. doi:10.1007/s10943-016-0213-z
Torgler, B., & Schaltegger, C. (2014). Suicide and Religion: New Evidence on the Differences Between Protestantism and Catholicism. Journal For The Scientific Study Of Religion, 53(2), 316-340. doi:10.1111/jssr.12117
Wu, A., Wang, J., & Jia, C. (2015). Religion and Completed Suicide: a Meta-Analysis. Plos ONE, 10(6), 1-14. doi:10.1371/journal.pone.0131715
The following is a presentation I prepared in 2012 on Suicide Awareness for delivery at Durham College. It’s just been sitting on my hard drive since then, so I’ve made it available for other organizations that wish to provide suicide awareness presentations. The content is reproduced below, and you can download the slides here. Although the content takes a Canadian focus, I’ve noted US statistics where possible.
A Note on Wording
Suicide True and False
Risk Factors for Suicide
Warning Signs for Suicide
How to Help
Currently Director of Online Support & Communication @ Distress Centre Durham
Distress Centre Durham History
1600+ hours of telephone experience
600+ hours of online chat and text
Former Placement Student, Summer Student (x3)
Distress Centre Durham Basic Training
DCIB Suicide Risk Assessment
Online Chat and Text (ONTX) Training
Before we start…
People do not commit suicide
You commit a crime, you get committed to a psychiatric hospital
Instead, people who take their own lives are said to have suicided or alternately died by suicide, as one dies of lung cancer or a person is murdered.
Suicide – Intentional taking of one’s own life
Suicidal ideation – Clinical term for suicidal thoughts
A suicidal attempt that is designed to fail or be discovered
Not necessarily attention-seeking behaviour
What is a Crisis?
A crisis is any event that overwhelms someone’s coping mechanisms, those things a person does to solve or deal with a problem
Suicide is the 2nd leading cause of death in Canada for 18-24 year olds (behind car accidents) (Statistics Canada, 2015)
More than 90% of suicide victims may have had diagnosable mental illness (Bertolote, et. al., 2004) – Note that there is still not consensus on this figure, it still makes an important point about mental health treatment for suicide
21,115 people died by suicide in Ontario in 2005
The suicide rate is 12.7 per 100,000 males and 4.1 per 100,000 females in Ontario (Statistics Canada, 2014a)
The Aboriginal suicide rate is 11 times higher than the national average (Public Health Agency of Canada, 2011)
Risk Factors for Suicide (CDC, 2016)
Clinical Depression, Borderline Personality Disorder (BPD), Schizophrenia all increase risk
Strong support network allows developing the resources that provides the strongest defence against suicide
Things that we do ourselves to cope with stress
Listening to music / Playing an Instrument
Running / Working Out / Exercise
Prayer / Meditation / Spirituality
Yoga / Massage
People in our “inner circle” we reach out to
Community agencies and others outside of our inner circle
Distress Lines (e.g. Distress Centre)
Psychiatrists / Psychologists
Durham Mental Health Services
Suicide is usually preventable
Asking about suicidal thoughts is the most important thing you can do
Never be afraid to reach out to a professional for help
The original training included a case study derived from Distress Centre Durham training materials.
American Association of Suicidiology (AAS). (n.d.) “Warning Signs | American Association of Suicidology. Retrieved on August 24, 2016 from www.suicidology.org/resources/warning-signs
Barber, C.W., Miller, M.J. (2014) Reducing a Suicidal Person’s Access to Lethal Means of Suicide: A Research Agenda. American Journal of Preventive Medicine. 47(3S2):S264–S272
Bertolote, J. M., Fleischmann, A., De Leo, D., & Wasserman, D. (2004). Psychiatric Diagnoses and Suicide: Revisiting the Evidence. Crisis: The Journal Of Crisis Intervention And Suicide Prevention, 25(4), 147-155. doi:10.1027/0227-5910.25.4.147
Centers for Disease Control and Prevention (CDC). (2011) Web-based Injury Statistics Query and Reporting System (WISQARS). National Center for Injury Prevention and Control. Retrieved on August 24, 2016 from http://www.cdc.gov/injury/wisqars/index.html.
Centers for Disease Control and Prevention (CDC). (2016) Suicide: Risk and Protective Factors. Retrieved on August 24, 2016 from http://www.cdc.gov/violenceprevention/suicide/riskprotectivefactors.html
Pompili, M., Serafini, G., Innamorati, M., Dominici, G., Ferracuti, S., Kotzalidis, G. D., … Lester, D. (2010). Suicidal Behavior and Alcohol Abuse. International Journal of Environmental Research and Public Health, 7(4), 1392–1431. http://doi.org/10.3390/ijerph7041392
Public Health Agency of Canada. The Human Face of Mental Health and Mental Illness in Canada 2006. Ottawa, ON: Public Health Agency of Canada, 2011. Available at: http://www.phac-aspc.gc.ca/publicat/human-humain06/
Shioiri, T., Nishimura, A., Akazawa, K., Abe, R., Nushida, H., Ueno, Y., & … Someya, T. (2005). Incidence of note-leaving remains constant despite increasing suicide rates. Psychiatry & Clinical Neurosciences, 59(2), 226-228. doi:10.1111/j.1440-1819.2005.01364.x
Statistics Canada. (2014a) “Suicides and suicide rate, by sex and by age group (Both sexes no.)” from CANSIM, table 102-0551. Retrieved from http://www.statcan.gc.ca/tables-tableaux/sum-som/l01/cst01/hlth66a-eng.htm on August 24, 2016.
Statistics Canada. (2014b) “Suicides and suicide rate, by sex and by age group (Both sexes no.)” from CANSIM, table 102-0551. Retrieved electronically from http://www.statcan.gc.ca/tables-tableaux/sum-som/l01/cst01/hlth66a-eng.htm on August 24, 2016.
Statistics Canada. (2015) Table 102-0561 – Leading causes of death, total population, by age group and sex, Canada, annual, CANSIM (database). Retrieved on August 24, 2016.
Statistics Canada. (2016) Navaneelan, T. Suicide rates: An overview. Retrieved on August 24, 2016 from www.statcan.gc.ca/pub/82-624-x/2012001/article/11696-eng.htm
There are a variety of sources related to Canadian suicide statistics, but no source effectively summarizes all of the statistics, with graphs and charts, and links back to the original citation. The purpose of this article is to provide the most up-to-date information on suicide by method, gender, province, age-range, and other characteristics. The most common source of data is Statistics Canada.
Suicide Rate in Canada
The overall rate for suicide in Canada is 11.3 per 100,000 based on the 2012 Statistics Canada data (released in 2015), for both genders. This is mostly unchanged from the 5 year average of 11.36 per 100,000. The next data will be released in 2017.
Although other countries may calculate suicide differently, Canada ranks approximately 70 for both sexes suicide, 70 for male suicides and 73 for female suicides (out of a total of 170 countries, where lower is better), based on 2012 data from the World Health Organization. (WHO, 2012)
Suicide by Age in Canada
The largest population of suicides in Canada are from men and women 45-59. All Ages data includes suicide of those of unknown age and those under 10.
Rate per 100,000 persons
% of Total
10 to 14
15 to 19
20 to 24
25 to 29
30 to 34
35 to 39
40 to 44
45 to 49
50 to 54
55 to 59
60 to 64
65 to 69
70 to 74
75 to 79
80 to 84
85 to 89
90 and older
Chart, Suicide by Age in Canada
Suicide by Gender in Canada
In Canada, like most countries, male suicides outnumber female suicides. (Statistics Canada, 2012)
Age at time of death
Male per 100,000
Female per 100,00 people
90 and older
The chart below shows the gross number of suicides in order to demonstrate the male percentage of the total. (Statistics Canada, 2012)
10 to 14
15 to 19
20 to 24
25 to 29
30 to 34
35 to 39
40 to 44
45 to 49
50 to 54
55 to 59
60 to 64
65 to 69
70 to 74
75 to 79
80 to 84
85 to 89
90 and older
Chart, Suicide by Gender in Canada
Suicide Attempts in Canada
Suicide attempts usually do not lead to suicide deaths. In the US, Han et. al. (2016) reported that in 2012, there were over 1.3 million suicide attempts and 39,426 suicide deaths, leading to a ratio of approximately 33 suicide attempts for every suicide death.
Statistics Canada (2016) notes a World Health Organization source that notes up to 20 suicide attempts for every suicide death.
Suicide Attempts by Gender in Canada
Females attempt suicide 1.5 times more often than males (Langlois & Morrison, 2002) Mustard, et. al. (2012) note that the rate of suicide attempts among women is 3 times that of men. Both sources are referred to in Statistics Canada (2016).
Suicide by Method in Canada
Suicide methods impact lethality, therefore it is important to understand the most common methods used to attempt suicide in Canada. Men are likelier to use more lethal means like hanging and firearm than women are (Bilsker & White, 2011) increasing their suicide lethality. 1998 data reveals the following gender breakdown by method for suicide (Langlois & Morrison, 2002)
Total Suicide Deaths
Total Poisoning Deaths
Jumping From High Place
Additionally, the following information is provided for poisonings (these numbers make up the total poisoning deaths number above):
Drugs and Medication
Motor Vehicle Exhaust
Other Carbon Monoxide
Chart, Suicide by Method in Canada
The above chart shows total poisoning deaths. The below chart breaks out poisoning into the various types:
Suicide by Province in Canada
Suicide in Canada has a distinct provincial impact, with northern territories having a higher rate of suicide and the Maritimes having a lower rate of suicide as compared to the provincial average. (Statistics Canada, 2016b)
Newfoundland and Labrador
Prince Edward Island
Chart, Suicide by Province in Canada
Youth Suicide in Canada
Youth suicide in Canada has been relatively stable for several years. Suicide is the 2nd leading cause of suicide in Canada for ages 15 to 34. (Statistics Canada, 2015a) Additionally, there are more suicide attempts in youth than adults, with Schwartz (2003) estimating between 50 and 200 attempts per youth suicide death.
It has been well-documented that the LGBT community has a higher rate of suicide than the general population.
Approximately 30% of suicide deaths and 28% of suicide attempts in Canada involve lesbian, gay or bisexual individuals. (LGB; Banks, 2003) The LGB population was estimated by Statistics Canada (2015c) at approximately 2%, though this is likely an underestimate.
The trans suicide rate is dramatically higher than the LGB rate. Between 20 and 40% of transgender individuals report suicide attempts, while a study of trans youth in Ontario reported that 35% had suicidal thoughts and 11% had a suicide attempt in the previous year. (Bauer, 2015)
Veteran/Military Suicide in Canada
Military member and military veteran suicide has increasingly been in the public consciousness. In 2012, the Canadian Forces had 10 suicide deaths by current members and 11 suicide attempts by current members according to a Global News article citing Department of National Defence data. (Minsky, 2015)
Given a strength of approximately 68,000 Regular Force members and 27,000 Reserve members, 10 suicides leads to a suicide rate per 100,000 of approximately 9.5, slightly lower than the general population rate of 13.1.
Bauer, G. R., Scheim, A. I., Pyne, J., Travers, R., & Hammond, R. (2015). Intervenable factors associated with suicide risk in transgender persons: a respondent driven sampling study in Ontario, Canada. BMC Public Health, 15(1), 1-15. doi:10.1186/s12889-015-1867-2
Banks, C. (2003) The Cost of Homophobia: Literature Review on the Human Impact of Homophobia On Canada. Community-University Institute for Social Research. Retrieved on August 27, 2016 from http://www.usask.ca/cuisr/sites/default/files/BanksHumanCostFINAL.pdf
Bilsker, D. & White, J. (2011) The silent epidemic of male suicide. BCMJ. 53(10) 529-534.. Retrieved on August 27, 2016 from www.bcmj.org/articles/silent-epidemic-male-suicide
Han, B., Kott, P. S., Hughes, A., McKeon, R., Blanco, C., & Compton, W. M. (2016). Estimating the rates of deaths by suicide among adults who attempt suicide in the United States. Journal Of Psychiatric Research, 77125-133. doi:10.1016/j.jpsychires.2016.03.002
Langlois, S & Morrison, P. (2012) Suicide deaths and suicide attempts. Health Reports. 13(2):9-21. Retrieved on August 26, 2016 from http://www.statcan.gc.ca/pub/82-003-x/2001002/article/6060-eng.pdf
Minsky, A. (2013, 4 Dec.) “For every suicide in the Canadian Forces, at least one attempt was recorded: documents”. Global News. Retrieved on August 27, 2016 from http://globalnews.ca/news/1009779/soldier-suicide-one-attempt-for-every-death/
Mustard, C., Bielecky, A., Etches, J., Wilkins, R., Tjepkema, M., Amick, B., Smith, P.M., Gnam, W.H. & Aronson, K. (2012). Suicide Mortality by Occupation in Canada, 1991-2001. Canadian Journal Of Psychiatry-Revue Canadienne De Psychiatrie, 55(6), 369-376.
Schwartz, M.W. (2003) The 5-minute Pediatric Consult. Lippincott Williams & Wilkins. pp 796.
Statistics Canada. (2015a) Table 102-0561 – Leading causes of death, total population, by age group and sex, Canada, annual, CANSIM (database). Accessed August 27, 2016.
Statistics Canada. (2015c) “Same-sex couples and sexual orientation… by the numbers” Retrieved on August 27, 2016 from http://www.statcan.gc.ca/eng/dai/smr08/2015/smr08_203_2015
Statistics Canada. (2016a) Table 102-0563 – Leading causes of death, total population, by sex, Canada, provinces and territories, annual, CANSIM (database). Retrieved on August 27, 2016 from http://www5.statcan.gc.ca/cansim/a47
Statistics Canada. (2016b) Navaneelan, T. Suicide rates: An overview. Retrieved on August 24, 2016 from www.statcan.gc.ca/pub/82-624-x/2012001/article/11696-eng.htm
World Health Organization (WHO). (2012) “GHO | By category | Suicide rates – Data by country.” Retrieved on August 27, 2016 from http://apps.who.int/gho/data/node.main.MHSUICIDE?lang=en
The Z-test is a simple tool for hypothesis testing that can be used to identify whether a mean result, when compared to a larger set is statistically significant when the larger set is a normal distribution.
Many datasets (for instance population height, test scores, etc.) have normal distributions. If you’re unsure whether your dataset has a normal distribution you can approximate and assume that it does if you have at least 30 items to draw on (e.g. 30 students heights, 30 test scores.)
You will need to know the population mean and the standard deviation in order to perform the one-sample z-test. If you don’t know the standard deviation you should use a t-test instead.
The following six steps are for a Z-test:
Identify our population, comparison distribution, hypothesis and assumptions. Choose an appropriate test.
State the null and research hypotheses.
Determine the characteristics of the comparison distribution.
Determine the cutoffs that indicate the points beyond which we reject the null hypothesis
Calculate the test statistic.
Decide whether to reject or accept (fail to reject) the null hypothesis.
One-Sample Z-Test Formula
The following is the formula for the z-test:
Where x̄ (x-bar) is the sample mean, ∆ (delta) is the value you are comparing it with (the population mean), σ (sigma) is the population standard deviation and n is the number of values in the larger set.
The example we will work with for our one-sample z-test is a set of students who received 4 hours of study strategies tutoring before beginning a statistics course and another set of students who did not. You can compare the grades of these students to find out if the tutoring has impacted their grades.
There are 150 students in the class. The mean score in the class (x-bar) is 72, with a SD of 6. The mean score of the 20 students who received tutoring (delta) is 75 with a SD of 5. These values seem too close for us to estimate purely by hand so we will use our formula. Plugging this into the formula, we get:
z = 75 – 73 / (5 / sqrt(150))
z = 75 – 73 / (5 / 12.25)
z = 75 – 73 / 0.41
z = 2 / 0.82
z = 2.44
Looking up 2.44 in our Z-Table gives us 49.27.
We subtract 49.27 from 50 (the mean) gives us 0.0073 (the % in tail value in the z-chart.) Because we are performing a two-tailed test (we want to know whether our value is significantly above or significantly below the mean), we multiply 0.0073 by to get a p value of 0.0146.
In order to reject the null hypothesis, our p value must be under 0.05. Because our p value is below 0.05, we reject the null hypothesis. This means that the students who received 4 hours of tutoring did have better grades than those who didn’t.