1. A sociologist working at McGill has credible past research giving him the average amount of crimes committed for all Canadian cities last year, as well as the standard deviation. The sociologist is curious about whether a new "de-escalate violence" campaign in Montreal has made the Montreal rate different from Canadian cities as a whole. Using data collected from a random sample of Montreal police stations he calculates the average amount of crimes reported in Montreal since the new campaign was launched. He wants to see if there is a real difference between the Montreal sample and the Canadian average.

a. What type of hypothesis test should he conduct - one or two sample?

b. Write out his null and research hypotheses for this scenario.

2. A researcher is interested in whether children living in cities watch the same amount of television as children living in rural areas. She determines the average hours of television watched per week in a sample of 24 urban children, and the average amount per week in a sample of 28 rural children. She sets alpha to .05 and calculates a test statistic of t = -2.71. Find the researcher's critical value and then indicate whether she should reject or retain the null hypothesis that there is no difference in the amount of hours of television watched per week among urban and rural children.

3. A researcher is interested in whether men and women have different attitudes towards the legalization of marijuana. Using an attitude scale where 1 = totally in favour and 10 = totally opposed he determines an average score for a sample of men and an average score for a sample of women. The researcher uses alpha = .05, and he computes a test statistic of z = 1.20.

a. Determine the researcher's p-value and then make a decision about whether to reject or retain the null hypothesis that men and women have the same attitudes toward the legalization of marijuana.

b. Interpret the researcher's findings.

4. A social psychologist is interested in gender differences in the sociability of teenagers. Using the number of good friends as an indicator of sociability, the researcher found that a random sample of females had on average 5.9 close friends (s=2.1; n=27) and a random sample of males had on average 3.8 close friends (s=1.6; n=35).Is the difference in sociability between males and females statistically significant? Set alpha to .01.

a. Step 1: Identify the type of hypothesis test and the population(s) and sample(s) here.

b. Step 2: Write out the null and research hypotheses.

c. Step 3: Determine the critical value.

d. Step 4: Compute the test statistic.

e. Step 5: Make a decision using the critical value (no need to use a p-value here - just work with your critical value!) and interpret the results.