Statistics DQ

Q-1: During recent seasons, Major League Baseball has been criticized for the length of the games. A report indicated that the average game lasts 3 hours and 30 minutes. A sample of 17 games revealed the following times to completion. (Note that the minutes have been changed to fractions of hours, so that a game that lasted 2 hours and 24 minutes is reported at 2.40 hours.)

2.98 2.40 2.70 2.25 3.23 3.17 2.93 3.18 2.80
2.38 3.75 3.20 3.27 2.52 2.58 4.45 2.45
Can we conclude that the mean time for a game is less than 3.50 hours? Use the .05 significance level.


Q-2: What is hypothesis testing?

Q-3: What is the value of performing hypotheses tests to solve problems related to business and operations management? Provide specific examples?

Q-4: A computer manufacturer is about to unveil a new, faster personal computer. The new machine clearly is faster, but initial tests indicate there is more variation in the processing time. The processing time depends on the particular program being run, the amount of input data, and the amount of output. A sample of 16 computer runs, covering a range of production jobs, showed that the standard deviation of the processing time was 22 (hundredths of a second) for the new machine and 12 (hundredths of a second) for the current machine. At the .05 significance level can we conclude that there is more variation in the processing time of the new machine? F=s21/s22

Q-5: When is the significance level chosen?

Q-6: What is a one tailed test?

Q-7: What is a two tailed test?