Chapter 7 & 8, Hypothesis testing for 1 - 2 populations

Question 1

How is the z-test & z-crit value calculated from a single sample when the population standard deviation is known?

Answer 1

T-crit from normal distribution

Question 2

How is the z-test & z-crit value calculated from a single sample with an unknown population variation calculated

Answer 2

z-crit from tn-1 distribution

Question 3

How is the z-test & z-crit value calculated from a propertion

Answer 3

use normal dist, when p is known

when p is unknown use p^ & Tn-1

Question 4

What is a type 1 error

Answer 4

Incorrectly reject a true null hypothesis

Question 5

What is a Type 2 error?

Answer 5

The failure to reject a false null hypothesis

Question 6

What is the standard formula for the z-test when there are two samples?

Answer 6

Question 7

What is the z-test value for the difference between two sample means when the two population variances are known. What is assumed in this model?

Answer 7

Populations are normally distributed. Samples are independent

Question 8

What is the z-test value for the difference between two samples means when the population variances are unknown? What is assumed? (How is the assumption tested?)

Answer 8

It is assumed the population variances are equal. This is tested by checking the ratio of the sample variances, it should not exceed 1.5. It is als assumed samples are independent and normally distributed.

Z-crit is from t(n1+n2-2) dist

Question 9

What is the z-test for the difference between two sample means when the samples are paired?

Answer 9

z-crit is from tn-1