Question

1. What is the difference between a z-test and a t-test? How do you know which test to use? (2pts)

For 2-5 show the following:

A)    List the symbolic set up of Ho and Ha ( Ho/Ha: symbol and (equality or inequality sign))

B)   List the conditions that must be met for the test and how they can be met (stated, what type of graph, CLT etc.

2.   Z or t test (2pts)

3.   One proportion z test (2pts)

4.   2 sample z or t test (2pts)

5.   2 sample proportion test or difference of proportion test (2pts)

Answer 1

1. z test is used when distribution is normal and population std. deviation is known, note that normality is usually taken when sample size is large ( > 30), whereas t test is used when, data follows normality and sample size is large (> 30), but population std. deviation is not known.