Use TI-83+ or TI-84 calculators. Show calculator function if the disreubution is on normacdf, invNorm or normalpdf.

62. Suppose that the distance of fly balls hit to the outfield (in baseball) is normally distributed with a mean of 250 feet and a standard deviation of 50 feet. We randomly sample 49 fly balls. a. If X = average distance in feet for 49 fly balls, then X ~ _______(_______,_______) b. What is the probability that the 49 balls traveled an average of less than 240 feet? Sketch the graph. Scale the horizontal axis for X . Shade the region corresponding to the probability. Find the probability. c. Find the 80th percentile of the distribution of the average of 49 fly balls.

67. Determine which of the following are true and which are false. Then, in complete sentences, justify your answers. a. When the sample size is large, the mean of X is approximately equal to the mean of . b. When the sample size is large, X is approximately normally distributed. c. When the sample size is large, the standard deviation of X is approximately the same as the standard deviation of .

70. Which of the following is NOT TRUE about the distribution for averages? a. The mean, median, and mode are equal. b. The area under the curve is one. c. The curve never touches the x-axis. d. The curve is skewed to the right.