Question

(1 point) 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
Test Score	74	87	75	71	83	85	95	67	97	90

Use a 0.050.05 significance level to test the claim that people do better with the new edition. Assume the standard deviation is 11.1. (Note: You may wish to use statistical software.)

(a) What kind of test should be used?

A. Two-Tailed
B. One-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. Yes
B. No

(e) Construct a 9595% confidence interval for the mean score for students using the new text.
<μ<<μ<

Answer 1

Sol:

Ho:mu=75

Ha:mu>75

since population standard deviation is given it z test

It is one tail and right tail test

B. One-Tailed

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

sample mean=sum of values/total=824/10=82.4

from ti83 cal

STAT>TESTS>ZTEST

The test statistic is Z=2.11

P=0.0175

p<0.05

Reject HO

Accept Ha

there sufficient evidence to support the claim that people do better than 75 on this exam

YES

B. One-Tailed

The test statistic is Z=2.11

P=0.0175

YES