Fowle Marketing Research, Inc., bases charges to a client on the assumption that telephone surveys can be completed in a mean time of 15 minutes or less. If a longer mean survey time is necessary, a premium rate is charged. Suppose a sample of 35 surveys shows a sample mean of 17 minutes. Use = 4 minutes. Is the premium rate justified?
a. Formulate the null and alternative hypotheses for this application.
H0:
Ha:
b. Compute the value of the test statistic
c. What is the p-value
d. Using = .01, is a premium rate justified for this client?