Chapter 8 Written Homework 1. A hypothesis test is conducted to test the claim that the proportion of people with dark hair at Moorpark is greater than 0.8. The researchers find that the test statistic is z = 2.19. a. Using = 0.05, draw a bell-shaped curve to represent the critical value approach. Be sure to label (This means find and label the critical value as well as the rejection and fail to reject regions). b. Based on your drawing would we reject of fail to reject? Explain.

we reject  H₀

Step-by-step explanation:  Se annex

The test is one tail-test (greater than)

Using   α = 0,05   (critical value )  from z- table we get

z(c) = 1,64

And Test hypothesis is:

H₀         Null hypothesis           μ   =  μ₀

Hₐ       Alternate hypothesis   μ   >  μ₀

Which we need to compare with z(s) = 2,19  (from problem statement)

The annex shows z(c), z(s), rejection and acceptance regions, and as we can see z(s) > z(c) and it is in the rejection region

So base on our drawing we will reject  H₀

your answer would be 10x - 1