9.22

Suppose you are testing H₀: p = .45 versus H_a:  p > .45. A random sample of 310 people produces a value of = .465. Use α = .05 to test this hypothesis.

 

            H₀: p = .45

            H_a: p > .45

            n = 310

            = .465

α = .05

 

From table A.5, z_Table = 1.95

 

This is a one-tailed test.

 

We consider this normally distributed because a large (310) sample is taken. Therefore we will use the z-formula:

 

 

 

 

Where

            = sample proportion

             p = population proportion

             q = 1 – p

 

 

 

 

The observed z-value is NOT greater than z_Table therefore we do NOT reject the null hypothesis.