:9. A box contains numbered tickets. The box average is supposed to be 20. 100 tickets are drawn from the box (with replacement). The average value of the numbers on these tickets turns out to be 19, and the standard deviation turns out to be 4. Let the null hypothesis be that the box average is 20, and let the alternate hypothesis be that the box average is less than 20. Using
z = (observed average - expected average)/SE(of average),
the P-value of the test is seen to be closest to
a. .6% b. 1.2% c. 12% d. 68% e. 95%