in formulating hypotheses for a statistical test of significance,

1. In formulating hypotheses for a statistical test of significance, the null hypothesis is often

A. the probability of observing the data you actually obtained. 

B. a statement that the data are all 0.

C. 0.05

D. a statement of “no effect” or “no difference.”

2. Supppose we are testing the null hypotheses H_0:mu = 20 and the alternative H_a:mu != 20, for a normal population with sigma = 5. A random sample of 25 observations are drawn from the population. Find the sample mean of these observations is x-bar = 17.6. The p-value is closet to 

a. 0.0082

b. 0.1336

c. 0.0164

d. 0.0660

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