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. We wish to test if the proportion of STAT 330 students who get A’s is less tha

ID: 3396611 • Letter: #

Question

. We wish to test if the proportion of STAT 330 students who get A’s is less than 25%. If T = 4.59 then at alpha = .01 what is the correct decision?

a. Reject Ho   b. do not reject Ho       c. accept Ho

2.   Classify the test in question one.

A. two-tailed         B. one tailed left           

C. zero tailed         D. one tailed right

3. P(type I error) =  

4. True or False. Alpha is the probability that the test statistic falls in the rejection region given the null hypothesis is a false statement.

5. True or False. Every time n > 30, then we can use the Z-test for testing if the population mean is equal to some specified value.

Explanation / Answer

We wish to test if the proportion of STAT 330 students who get A’s is less than 25%. If T = 4.59 then at alpha = .01 what is the correct decision?

This is left tailed test but test statistic is positive. This means, p-value is greater than 0.5. Therefore, do not reject null hypothesis at = 0.01. Therefore, correct option is:

b. do not reject H0

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2.   Classify the test in question one.

Since alternative hypothesis is less than type, this is left tailed test. Therefore, correct option is:

B. one tailed left          

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3. P(type I error) = Level of significance = 0.01

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4. False. Alpha is the probability of type I error.

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5. True. Every time n > 30, then we can use the Z-test for testing if the population mean is equal to some specified value.