refer to pciture

In a study, the mean number of days that 123 adolescents in substance abuse treatment used medical marijuana in the last 8 months was 108.33. Assuming the population standard deviation is 29 days, a 90% confidence interval for the mean number of days, u, of medical marijuana use in the last 8 months of all adolescents in substance abuse treatment is from 104.03 to 112.63, and a 95% confidence interval for the mean is from 103.21 to 113.45. Complete parts (a) through (c) 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. Determine the margin of error for the 90% confidence interval. day(s) (Round to two decimal places as needed.) b. Determine the margin of error for the 95% confidence interval. day (s ) (Round to two decimal places as needed.) c. Compare the margins of error found in parts (a) and (b). What principle is being illustrated