QUESTION 2

1. Check all that are true about the t distribution: Check only the responses that are true.

		There is a single t distribution for all sample sizes
		The t distribution(s) have wider tails than the Standard Normal Distribution.
		It is used when population standard deviation is estimated from a sample.
		The t distribution can only used for small sample sizes.

QUESTION 3

1. When standard deviation is estimated from a sample, which distribution will provide a more reliable result for hypothesis testing and confidence interval estimation?

		Normal distribution
		t distribution

QUESTION 4

Your tolerance for type one error is alpha = 0.05. If it had been alpha = 0.01 instead given the same sample size (degrees of freedom) the critical value for t would have been higher..

True

False

QUESTION 7

Match the following decisions with the corresponding statistical terminology:

- A. B. C. D.	Concluding that infants who ultimately died of SIDS have lower birthweight than other full-term births, when in fact there is no difference.
- A. B. C. D.	Correctly concluding that the birthweight of infants who ultimately died of SIDS is the same as other full-term births, when in fact there is a difference.
- A. B. C. D.	Correctly concluding that infants who ultimately died of SIDS have lower birthweight than other full-term births, when this difference does in fact exist.
- A. B. C. D.	Concluding that the birthweight of infants who ultimately died of SIDS is no different than other full-term births, when there is in fact no difference.

A.	Type II error
B.	Correctly failing to reject the null hypothesis.
C.	Correct rejection of the null hypothesis.
D.	Type I error