1. A random sample of 10 parking meters in a beach community showed the following incomes for a day. Assume the incomes are normally distributed.

$3.60, $4.50, $2.80, $6.30, $2.60, $5.20, $6.75, $4.25, $8.00, $3.00.

1. Find the 95% confidence interval for the true mean.

2. We ask whether people will score higher or lower on a questionnaire of their well-being when they are exposed to sunshine compared to when they're not exposed to sunshine. A sample of 8 people is first measured after low levels of sunshine exposure and then again after high levels of exposure. We get the following pairs of scores:

Low: 14 13 17 15 18 17 14 16

High: 18 12 20 19 22 19 19 16

1. State the null and alternative hypotheses.
2. Using an alpha = 0.05, what is t (_crit)?
3. Using SPSS, calculate t (_obt)) (Use paired/related sample t test to obtain this info)
4. What should you conclude?

3. We investigate the effects of sensitivity training on a policeman's effectiveness at resolving domestic disputes (comparing independent samples of policemen who had or had not completed the training). The dependent variable was their ability to successful resolve domestic disputes. The following scores were obtained:

No course	Course
11	13
14	16
10	14
12	17
8	11
15	14
12	15
13	18
9	12
11	11

1. State the null and alternative hypotheses.
2. Using an alpha = 0.05, what is t (_crit)?
3. Using SPSS, calculate t (_obt) (Use Independent Samples t test to get this info)
4. What should you conclude?