Margin of Error Calculations

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

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

A sample of n students were asked for the average amount of money they spend in a day. The data resulted in a mean of $5.50 with a standard deviation of $2.45. If the margin of error was $0.31, how many students were in the sample? Round to the nearest whole student

• 250

• 16

• 100

• 500

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

A research team surveys 200 high schoolers at glenoak. They find that 57% of them drive to school every day. What is the margin of error?

• 95%

• 14%

• 7%

• 3%

A sports analyst for an NBA team surveyed 50 games. The average points per game was 113 with a standard deviation of 5.6. Find the Margin of Error with 90% Confidence.

Identify the variables used in the Margin of Error formula

• 50

• 1.645

• Z

• 5.6

• n

A sports analyst for an NBA team surveyed 50 games. The average points per game was 113 with a standard deviation of 5.6. Find the Margin of Error with 90% Confidence. Identify the variables used in the Margin of Error formula

• 50

• 5.6

• Z

• 1.645

• n

A random sample of 40 bags of Doritos was obtained. The mean weight was 15.5 oz with a standard deviation of 0.2 oz. At a 95% confidence level, find the margin of error of the sample.

At the Greenville County Cross Country Championships, a college scout took a sample of 20 runners. The average time was 17.25 minutes with a standard deviation of .03. Find the Margin of Error with 99% Confidence.

• 20

• .03

• n

• 2.58

• Z

The confidence interval created was between $44-$56.

What was the margin of error?

• $4

• $50

• $6

• $12