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A study is conducted to determine if a newly designed text book is more helpful

ID: 3072951 • Letter: A

Question

A study is conducted to determine if a newly designed text book is more helpful to learning the material than the old edition. The mean score on the final exam for a course using the old edition is 75. Ten randomly selected people who used the new text take the final exam. Their scores are shown in the table below.

Person A B C D E F G H I J

Score 70 95 87 73 97 86 69 80 90 78

Use a 0.05 significance level to test the claim that people do better with the new edition. Assume the standard deviation is 10.4. (Note: You may wish to use statistical software.) (a) What kind of test should be used?

A. One-Tailed:

B. Two-Tailed:

C. It does not matter:

(b) The test statistic is (rounded to 2 decimals).

(c) The P-value is

(d) Is there sufficient evidence to support the claim that people do better than 75 on this exam? A. No B. Yes

(e) Construct a 95% confidence interval for the mean score for students using the new text. <

Explanation / Answer

The statistical software output for this problem is:

One sample Z hypothesis test:
: Mean of variable
H0 : = 75
HA : > 75
Standard deviation = 10.4

Hypothesis test results:

95% confidence interval results:

Hence,

a) One-tailed

b) Test statistic = 2.28

c) P - value = 0.0113

d) Yes

e) 95% confidence interval:

76.05 < < 88.95

Variable n Sample Mean Std. Err. Z-Stat P-value Score 10 82.5 3.2887688 2.2804887 0.0113