Ascott J EX 9-com.docx - Ascott Jennifer ex 9 1 Consider...

Ascott Jennifer ex 9 6/5/2019
1. Consider this hypothesis test:
H
0
: p
1
- p
2
= 0
H
a
: p
1
- p
2
> 0
Here p
1
is the population proportion of “yes” of Population 1 and p
2
is the population proportion
of “yes” of Population 2. Use the statistics data from a simple random sample of each of the two
populations to complete the following: ( 8 points )
Population 1 Population 2
Sample Size (n) 400 600
Number of “yes” 300 426
a. Compute the test statistic z.
b. What is the p-value?
c. Should H
0
be rejected? Use the p-value and a level of significance of 0.05 to
justify your answer.
d. Use the above data to construct a 95% confidence interval for p
1
- p
2
0.75-0.71± 1.96 x SQRT (0.75(1-0.75)/400+0.71(1-0.71/600))
= 0.04± 0.056
= -0.006, 0.096

Ascott Jennifer ex 9 6/5/2019