Margin of Error Basics

For a class project, a student in a statistics class surveys the monthly rent for 32 unfurnished one-bedroom apartments in Boston and finds the mean monthly rent to be $1400 with a standard deviation of $220. Find the margin of error for the sample mean. (assuming 95% confidence) Round to the nearest hundredth

• $77.78

• $4.31

• $188.78

• $494.97

Complete the following statement about the change in size. If you increase the size of your sample, the ME will . . . .

• increase

• decrease

• stay the same

A researcher wishes to estimate, within $25, the true mean amount of postage a community college spends each year. The standard deviation is known to be $80. If she wishes to be 95% confident in her estimate of the true mean amount of postage, how large a sample is necessary? Round to the nearest whole number

• 41

• 25

• 80

• 200

Researchers want to estimate with 95% confidence the true mean pulse rate of American adult males who jog at least 15 miles per week. They survey 21 males and find the sample mean pulse rate to be 52.6 beats per minute and a standard deviation of 3.22 beats per minute. Find the margin of error for the mean pulse rate of all American adult males who jog at least 15 miles per week. Round to the nearest tenth.

• 1.4 beats per minute

• 1.7 beats per minute

• 0.9 beats per minute

• 4.1 beats per minute

The amount added and subtracted to the statistic.

• Margin of Error

• Point Estimator

• Statistic

• Population

The amount added and subtracted to the statistic.

• Margin of Error

• Confidence Interval

• Z Score

• Population

Complete the following statement about the change in size. If you increase the size of your sample, the Margin of Error will . . . .

• increase

• decrease

• stay the same

The total value to be added/subtracted from the test statistic to find the interval max/min.

• Critical Value

• Z-score

• Margin of Error

• Standard Error

Margin of error equals:

• Critical Value ∗ standard Error

• z*

• 1.96

• Standard Error

How could Javier decrease the margin of error?

• Increase the sample size

• Decrease the sample size