1. One student was upset with her grade on Test 2 and thought the test was too difficult. In her anger, she said, "There is no way the class average on this test was higher than a C." Can you conclude at a 0.05 level of significance that the average score on Test 2 was no higher than a 79?

Question

Mathematics

Alaina Hall

7 October, 17:52

1. One student was upset with her grade on Test 2 and thought the test was too difficult. In her anger, she said, "There is no way the class average on this test was higher than a C." Can you conclude at a 0.05 level of significance that the average score on Test 2 was no higher than a 79?

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Answers (1)

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Timothy · Answer 1

Hypothesis rejected

Step-by-step explanation:

Lets use the t-test since the variance of the population is now known. We need to test the hypothesis that H_0: / mu / leq 79 / text{ vs } H_1: / mu > 79. This is performed in R as follows:

t. test (tt$Test. 2. Score, mu=79, alternative="greater")

One Sample t-test

dа ta: tt$Test. 2. Score

t = 2.9238, df = 69, p-value = 0.002337

alternative hypothesis: true mean is greater than 79

95 percent confidence interval:

81.26555 Inf

sample estimates:

mean of x

84.27143

Thus, we reject the null hypothesis and conclude that / mu > 79.