# Confidence Intervals

Random sampling from two normal populations produced the following results:

Xbar1= 63, s1= 18 n1=50

xbar2= 60 s2 = 7 n2 = 45

a. Estimate with 90% confidence the difference between the two population means.

b. Repeat part a changing the sample standard deviations to 41 and 15 respectively.

c. What happens when the sample standard deviations increase?

d. Repeat part a doubling the sample size.

e. Describe the effects of increasing the sample sizes.

https://brainmass.com/statistics/confidence-interval/confidence-intervals-458838

#### Solution Preview

Problem:

Random sampling from two normal populations produced the following results:

Xbar1= 63, s1= 18 n1=50

xbar2= 60 s2 = 7 n2 = 45

a. Estimate with 90% confidence the difference between the ...

#### Solution Summary

This solution is comprised of detailed step-by-step calculation and analysis of the given problem and provides students with a clear perspective of the underlying concepts.