Refer to Exercise 8.77.

a. The mean number of days that 30 adolescents in substance abuse treatment used medical marijuana in the last 6 months was 105.43. Find a 95% confidence interval for μ based on that data.

b. Compare the 95% confidence intervals obtained here and in Exercise 8.77(a) by drawing a graph similar to Fig. 8.7.

c. Compare the margins of error for the two 95% confidence intervals.

d. What principle is being illustrated?

Exercise 8.77

An issue with legalization of medical marijuana is “diversion,” the process in which medical marijuana prescribed for one person is given, traded, or sold to someone who is not registered for medical marijuana use. Researchers S. Sautel et al. study the issue of diversion in the article “Medical Marijuana Use Among Adolescents in Substance Abuse Treatment” The mean number of days that 120 adolescents in substance abuse treatment used medical marijuana in the last \6 months was 102.72. Assume the population standard deviation is 32 days.

Fig. 8.6

Transcribed Image Text:

FIGURE 8.7 95% confidence intervals for with sample sizes 50 and 200 38.0 We can be 95% confident that μ lies in here 40.5 I 41.4 We can be 95% confident that μlies in here 1 42.2 43.9 44.8 (n = 200) (n = 50)