In a study, the mean number of days that 115 adolescents in substance abuse treatment used medical marijuana in the last 6 months was 99.45. Assuming the population standard deviation is 34 days, a 99% confidence interval for the mean number of days, , of medical marijuana use in the last 6 months of all adolescents in substance abuse treatment is from 91.28 to 107.62 , and a 90% confidence interval for the mean is from 94.23 to 104.67. 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 99% confidence interval. day(s) (Round to two decimal places as needed.)