Margin of Error and Confidence Level

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

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 95% confidence interval for the population mean Round to the nearest hundredth

• [1322.22, 1477.78]

• [1395.69, 1404.31]

• [1211.22, 1588.78]

• [905.03, 1894.97]

A sample of 121 high school seniors were surveyed on their level of school spirit on a scale of 0-100. The sample mean of this survey is 86. The known population standard deviation is 14 for all seniors in the class. Which of these is a 95% confidence interval for the population mean?

• [82.7, 89.3]

• [83.5, 88.5]

• [83.9, 88.1]

• [85.9, 86.1]

How do you calculate the margin of error for a 95% confidence interval?

• Multiply the standard deviation by 1.96 and divide by the square root of the sample size.

• Divide the standard deviation by 1.96 and multiply by the square root of the sample size.

• Multiply the standard deviation by the square root of the sample size.

• Divide the standard deviation by the square root of the sample size.

The amount added and subtracted to the statistic.

• Margin of Error

• Confidence Interval

• Z Score

• Population

Margin of Error is equal to:

• Standard Deviation

• 2 * Standard Deviation

• Critical Value

• Point Estimate

The National Honor Society at Central High School plans to sample a random group of 100 seniors from all high schools in the state to determine the average number of hours per week spent on homework. A 95 percent confidence interval for the mean number of hours spent on homework will then be constructed using the sample data. Before selecting the sample, the National Honor Society decides that it wants to decrease the margin of error. Which of the following is the best way to decrease the margin of error?

• Increase the confidence level to 99%

• Use the population standard deviation

• Use the sample standard deviation

• Decrease the sample size

• Increase the sample size

The amount added and subtracted to the sample statistic.

• Margin of Error

• Point Estimator

• Statistic

• Population

The amount added and subtracted to the statistic.

• Margin of error

• Statistic

• Population

• Point estimator