13.An experiment was conducted to compare the mean length of time required for two First National Bank of Anchorage employees to complete the paperwork for opening new customer personal checking accounts. Fifteen customers were randomly assigned to each employee and the length of servicing time was recorded in minutes for each customer.
Employee “A”
Sample Mean=13.3min. Sample Std Dev=4.2 min
Employee”B”
Sample Mean=14.5min Sample Std. = 3.4 min
Do the data provide sufficient evidence to indicate that Employee “A” is more efficient than Employee “B” in opening new customer checking accounts? Test the null hypothesis using a ten percent significance level. Assume the population standard deviation is unknown. Use the t-pooled test procedure.
14. Dr. Hillary Clinton, Director for Apple Computer Systems in Unalakleet, Alaska wishes to estimate the “population mean age” of full-time students enrolled at the University utilizing the Apple Computer as their primary computer tool. She selects a random sample of 8 students, and determines the sample mean age to be 34.65 years with a sample standard deviation of 12.57 years. Construct a ninety-nine percent confidence interval of the population mean age.
Assume the population standard deviation is unknown. Use the “t” procedure