Statistics

Read Chapter 10: Inference About Means and Proportions with Two Populations Link to Chapter 10a PowerPoint Slides ,  Link to Chapter 10b PowerPoint Slides

· Complete and submit exercises

· Methods, pages 451-452: 1 and 2

· Methods, page 459: 9

· Methods. page 465: 19

1)The following results come from two independent random samples taken of two populations.

Sample 1	Sample 2
n1=50	n2=35
x¯1=13.6	x¯2=11.6
σ1=2.2	σ2=3.0

a. What is the point estimate of the difference between the two population means?

b. Provide a 90% confidence interval for the difference between the two population means.

c. Provide a 95% confidence interval for the difference between the two population means.

2) Consider the following hypothesis test.

H0:μ1-μ2≤0 Ha:μ1-μ2>0

The following results are for two independent samples taken from the two populations.

Sample 1	Sample 2
n1=40	n2=50
x¯1=25.2	x¯2=22.8
σ1=5.2	σ2=6.0

a. What is the value of the test statistic?

b. What is the p-value?

c. With α=.05, what is your hypothesis testing conclusion?

9)The following results are for independent random samples taken from two populations.

Sample 1	Sample 2
n1=20	n2=30
x¯1=22.5	x¯2=20.1
s1=2.5	s2=4.8

a. What is the point estimate of the difference between the two population means?

b. What is the degrees of freedom for the t distribution?

c. At 95% confidence, what is the margin of error?

d. What is the 95% confidence interval for the difference between the two population means?

19)Consider the following hypothesis test.

H0:μd≤0 Ha:μd>0

The following data are from matched samples taken from two populations.

	Population
Element	1	2
1	21	20
2	28	26
3	18	18
4	20	20
5	26	24

a. Compute the difference value for each element.

Answer ↓

b. Compute d¯.

Answer ↓

c. Compute the standard deviation sd.

Answer ↓

d. Conduct a hypothesis test using α=.05. What is your conclusion?

Answer ↓