Duplicate of Confidence Interval Review

Question 1

Determine whether or not this is a means problem or a proportions problem.

Accepted Answer

Means

Question 2

Construct a 90% confidence interval for the true proportion.

Accepted Answer

(0.595, 0.645)

Question 3

Determine which distribution to use, if any.

Accepted Answer

t-distribution

Question 4

As the confidence level increases, the confidence interval gets __________.

Accepted Answer

wider

Question 5

Determine whether this is a means or a proportions problem.

Accepted Answer

Proportions

Question 6

Find the minimum sample size needed to have a 4% margin of error with 99% confidence.

Accepted Answer

977

Question 7

Find the minimum sample size.

Accepted Answer

34

Question 8

Determine the za/2 for a 90% confidence interval

Accepted Answer

1.645

Question 9

As the sample size increases, the confidence interval gets __________.

Accepted Answer

narrower

Question 10

Identify the ta/2 for a 95% confidence interval.

Accepted Answer

2.447

Question 11

A confidence interval is the ____________ plus or minus the __________ .

Accepted Answer

Point Estimate, Margin of Error

Question 12

Find a 95% confidence interval for the mean.

Accepted Answer

(6510, 7138)

Question 13

Determine which distribution to use, if any.

Accepted Answer

z-distribution

Questions 13