Answer Happy

8.13a
In a study, the mean number of days that 124 adolescents in substance abuse treatment used medical marijuana in the last 6 months was 101.42. Assuming the population standard deviation is 32 days, a 95% confidence interval for the mean number of days, μ, of medical marijuana use in the last 6 months of all adolescents in substance abuse treatment is from 95.79 days to 107.05 days; this interval's margin of error is 5.63 days. Complete parts (a) through (d) below. Click here to view page 1 of the table of areas under the standard normal curve. Click here to view page 2 of the table of areas under the standard normal curve. a. The mean number of days that 31 adolescents in substance abuse treatment used medical marijuana in the last 6 months was 104.07. Find a 95% confidence interval for μ based on that data. The 95% confidence interval is from (Round to two decimal places as needed.) day(s) to day(s).