A physician employed by a large corporation believes that employees have gained body fat as a result of working from home during the pandemic.In 1970, the corporation measured the percentage of body fat for every employee.The scores were normally distributed with a mean of 22% body-fat.The physician measures the body fat percentage in a random sample of 12 workers employed by the corporation.The fat percentages found were as follows: 23, 39, 28, 31, 32, 24, 15, 22, 18, 25, 16, 27.

a)What is the mean and standard deviation of the sample (3 marks)?

b)Use a one-tailed test with = .05 to determine whether the physician's beliefs are accurate (9 marks).

c)Report and interpret the effect size using cohen's d (3 marks).

d)Report and interpret the 99% confidence interval (4 marks).