The average number of miles a person drives per day is 30. A researcher wishes to see if people over age of 60drive less than 30 miles a day.She selects a random sample of 43 drivers over the age of 60 and finds that the mean number of miles driven is 29.2.The population standard deviation is 3.2miles. At 0.05 level of significance, is there sufficient evidence that those drivers over 60 years old drive less than 30 miles per day on average? Assume that the variable is normally distributed.

Express your answers correct to 2 decimal places.

a) What test should be performed (z or t)? Type the corresponding letter.

b) Find the critical value(s). If there are 2 values (2 -tail test), separate them with a coma.

c) Calculate the test statistic

d) Make a decision. Type a) if you choose to "Reject the null hypothesis"; Type b) if you choose to "Fail to reject the null hypothesis".