Confidence Interval and Margin of Error

If the margin of error in a confidence interval is 4, what is the range of the confidence interval around a sample mean of 50?

• 46 to 54

• 48 to 52

• 45 to 55

• 49 to 51

For a given confidence level, if the margin of error is 3 and the sample mean is 50, what is the lower bound of the confidence interval?

• 47

• 53

• 50

• 49

A confidence interval for the mean score of a test is (75, 85). What is the margin of error?

• 5

• 10

• 15

• 20

If the sample mean is 100 and the margin of error is 5, what is the upper bound of the 95% confidence interval?

• 95

• 105

• 100

• 110

When a confidence level is increased, the margin of error​ (a)   and the confidence interval becomes (b)   .

• increases

• wider

• decreases

• narrower

The amount added and subtracted to the statistic.

• Margin of error

• Statistic

• Population

• Point estimator

The amount added and subtracted to the sample statistic.

• Margin of Error

• Point Estimator

• Statistic

• Population

You are given two sets of data measuring the same information, both with the same sample size. Set A has a larger Standard Error than Set B. If you were looking for a 99.8% Confidence Interval, which set would have a larger Margin of Error?

• Set A

• Set B

• Not enough information

• I have no idea what you're asking me to do

A recent survey of 2000 high schoolers found that 80% use their phones more than 4 hours a day on average. What is the interval for which we could expect to find the truth of the population?

• 2%

• 78% - 82%

• 93% - 97%

• 82%

Complete the equation: 
point estimate +/- _____

• standard deviation

• margin of error

• critical value

• confidence level