a sample of 35 people were taken to investigate drinking behaviour.

a) according to the sample 7.6% of people between 18- 25 yr olds have consumed alcohol with a deviation of 2.7 construct a 98% confidence interval for the true proportion of 18 - 25 yr olds who have consumed alcohol,

b) the same sample showed they spend 8 hours drinking a week with a standard deviation of 1.5 hrs. construct a 95% confidence interval for the true mean of times they drink a week.

c) based on the info in b, knowing the standard deviation of 2.05 hrs a week, construct a 98% confidence interval for the true mean of times they drink a week.