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1) Consider a test for ? . If the p-value is such that you can reject the null a

ID: 3368796 • Letter: 1

Question

1) Consider a test for ?. If the p-value is such that you can reject the null at the 5% significance level, can you always reject it at a 1% level of significance?

Yes. If the null is rejected at the 5% level it will always also be rejected at the 1% level.

No. If the p-value lies above .01 you would reject at the 5% level of significance but not at the 1% level.

No. If the p-value lies above .05 you would reject at the 5% level of significance, but not at the 1% level.

No. If the p-value lies between .01 and .05 you would reject at the 5% level of significance, but not at the 1% level.

2.A toothpaste manufacturer wishes to test the hypothesis that its new formulation gives users improved protection. The null hypothesis for this test is:

"The new formulation does not improve protection."

The alternative hypothesis is :

"The new formulation does improve protection."

Which of the following decisions about the null hypothesis would be a Type I error?

The company concludes that the change in the formula does not decrease protection, when in fact it does decrease protection.

The company concludes that the change in formula improves protection, when in fact it does not.

The company concludes that the change in the formula does not improve protection, when in fact it does.

The company concludes that the change in formula decreases protection, when in fact it does not.

a.

Yes. If the null is rejected at the 5% level it will always also be rejected at the 1% level.

b.

No. If the p-value lies above .01 you would reject at the 5% level of significance but not at the 1% level.

c.

No. If the p-value lies above .05 you would reject at the 5% level of significance, but not at the 1% level.

d.

No. If the p-value lies between .01 and .05 you would reject at the 5% level of significance, but not at the 1% level.

Explanation / Answer

Question 1)

Rejection of null hypothesis

If p value < alpha

Therfore, answer is

Option D)

No. If the p-value lies between .01 and .05 you would reject at the 5% level of significance, but not at the 1% level.