Retention Test Scores A sample of non-English majors at a selected college was used in a study to see if the student retained more from reading a 19th-century novel or by watching it in DVD form. Each student was assigned one novel to read and a different one to watch, and then they were given a 100-point written quiz on each novel. Assume the variables are normally distributed. The test results are shown below.

Book 85 85 84 91 86 90 80 90

DVD 85 86 82 89 88 75 70 80

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At =0.05, can it be concluded that the book scores are higher than the DVD scores?

(c) Compute the test value. Round the answer to at least three decimal places.

t=?

2.Obstacle Course Times An obstacle course was set up on a campus, and 8 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 below. Is there sufficient evidence at =0.05 to conclude that the students did better the second time? Assume the variables are normally distributed.

Student 1 2 3 4 5 6 7 8

Before 82 69 68 75 76 81 77 67

After 78 65 70 68 73 76 73 68

(c) Compute the test value. Round the sample statistics and final answer to at least three decimal places.

t=?

3.Cholesterol Levels A medical researcher wishes to see if he can lower the cholesterol levels through diet in 6 people by showing a film about the effects of high cholesterol levels. The data are shown. At =0.10, did the cholesterol level decrease on average? Use the critical value method and tables.

Patient 1 2 3 4 5 6

Before 244 215 213 221 206 218

After 216 201 194 192 203 214

(c) Compute the test value. Round intermediate calculations and final answers to at least three decimal places.

t-value=?

4.PGA Golf Scores At a recent PGA tournament (the Honda Classic at Palm Beach Gardens, Florida) the following scores were posted for eight randomly selected golfers for two consecutive days. At =0.10, is there evidence of a difference in mean scores for the two days? Assume the variables are normally or approximately normally distributed and use D for the mean on Thursday minus the mean on Friday.

Golfer 1 2 3 4 5 6 7 8

Thursday 70 69 68 70 66 64 65 67

Friday 69 70 75 70 67 74 67 68

(c) Compute the test value. Round the answer to at least three decimal places.

t=?

Overweight Dogs A veterinary nutritionist developed a diet for overweight dogs. 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. Eight overweight dogs were randomly selected from her practice and were put on this program. Their initial weights were recorded, and then they were weighed again after 4 weeks. At the 0.10 level of significance, can it be concluded that the dogs lost weight? Assume the variables are normally distributed.

Before 65 40 52 36 45 50 39 42

After 58 42 47 34 41 47 38 39

(c) Compute the test value. Round the intermediate calculations and final answer to at least three decimal places.

t=?