An electrical engineer is reporting one the results for a process that manufactures high-voltage supplies with a nominal output of 350 V. The production team is concerned that the process is beginning to produce power supplies with a true mean output voltage greater than the nominal value. The voltages for the last four power supplies tested are:
351.4 351.5 351.2 351.7
a. Perform an appropriate hypothesis test using a 10% signicance level. Give all ve steps.
b. Construct a 90% condence interval for the true mean voltage.
c. Discuss your conclusions about this manufacturing process based on the results of the hypothesis test and the condence interval.