Question

Given two independent random samples with the following results:

n1=11

x‾1=128

s1=23  

n2=13

x‾2=110

s2=32

Use this data to find the 95%95% confidence interval for the true difference between the population means. Assume that the population variances are equal and that the two populations are normally distributed.

Copy Data

Step 1 of 3:

Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.

Step 2 of 3:

Find the standard error of the sampling distribution to be used in constructing the confidence interval. Round your answer to the nearest whole number.

Step 3 of 3:

Construct the 95%95% confidence interval. Round your answers to the nearest whole number.

Answer 1

The statistical software output for this problem is:

From above output:

Step - 1: Critical value = 2.074

Step - 2: Standard error = 11.580

Step - 3: 95% confidence interval:

Lower = -6

Upper = 42