# 9.11: Chapter Solution (Practice + Homework)

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38.

a right-tailed test

40.

a left-tailed test

42.

This is a left-tailed test.

44.

This is a two-tailed test.

45.

1. 47.

c

1. 51.

b

d

55.

d

56.

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c

c

77.

1. 79.
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1. $$H_0: \mu \geq 150 H_a: \mu < 150$$
2. $$p$$-value = 0.0622
3. alpha = 0.01
4. Do not reject the null hypothesis.
5. At the 1% significance level, there is not enough evidence to conclude that freshmen students study less than 2.5 hours per day, on average.
6. The student academic group’s claim appears to be correct.