1) An obstacle course was set up on a campus, and 8 randomly selected volunteers were given a chance to complete it while they were being timed. They then sampled a new energy drink and were given the opportunity to run the course again. The “before” and “after” times in seconds are shown. Is there sufficient evidence at = 0.05 to conclude that the students did better the second time? Discuss possible reasons for your results.
2) At a recent PGA tournament, the following scores were posted for eight randomly selected golfers for two consecutive days. At = 0.05, is there evidence of a difference in mean scores for the two days?
3) A veterinary nutritionist developed a diet for overweight dog. The total volume of food consumed remains the same, but one-half of the dog food is replaced with a low-calorie “filler” such as canned green beans. Six overweight dogs were randomly selected from her practice and were put on this program. Their initial weights were recorded, and they were weighed again after 4 weeks. At the 0.05 level of significance, can it be concluded that the dogs lost weight?
4) Find p and q for each.
a) N = 36, X = 20
b) N = 50, X = 35
c) N = 64, X = 16
d) N = 200, X = 175
e) N = 148, X = 16
5) Find each X, given p.
a) P = 0.24, n = 300
b) P = 0.09, n = 200
c) P = 80%, n = 500
d) P = 40%, n = 480
e) P = 32%, n = 700
6) Find p and q
a) X1 = 6, n1 = 15, X2 = 9, n2 = 15
b) X1 = 21, n1 = 100, X2 = 43, n2 = 150
c) X1 = 20, n1 = 80, X2 = 65, n2 = 120
d) X1 = 15, n1 = 50, X2 = 3, n2 = 12
e) X1 = 24, n1 = 40, X2 = 18, n2 = 36
7) In a random sample of 200 men, 130 said they used seat belts. In a random sample of 300 women, 63 said they used seat belts. Test the claim that men are more safety-conscious that women, at = 0.01. Use the P-value method.
