6 Dog Bites to Postal Workers For a certain urban area in a

6. Dog Bites to Postal Workers For a certain urban area, in a sample of 5 months, an average of 28 mail carriers were bitten by dogs each month. The standard deviation of the sample was 3. Find the 90% confidence interval of the true mean number of mail carriers who are bitten by dogs each month. Assume the variable is normally distributed. (7-2)

Solution

28±1.645*3/sqrt 5 = (25.8, 30.2)