Margin of Error and Sample Size

A research team surveys 1001 adults, asking them how many hours they work per week. What is the margin of error for this survey?

• 3%

• 32%

• 63%

• 9%

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%

Why is a sample of 1000 people better than a sample of 100 people?

• It reduces the margin of error.

• It decreases bias.

• Having more people is always better.

• More people means that our results are more accurate.

Many years ago, a New York Times Poll on women’s issues interviewed 1025 women randomly selected from the United States, excluding Alaska and Hawaii. One question was “Many women have better jobs and more opportunities than they did 20 years ago. Do you think women had to give up too much in the process, or not?” 48% of women in the sample said “Yes.” What is the sample size for this survey?

• 1025

• American Adult Women

• American Adults

• 48%

How could Javier decrease the margin of error?

• Increase the sample size

• Decrease the sample size

• A

• B

• C

• D

What can you do to reduce the margin of error? 

• increase sample size

• decrease sample size

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

The operations manager of a large production plant wants to estimate the mean amount of time a worker takes to assemble a new electric component. Assume the standard deviation of the assembly time is 3.6 minutes. How many workers should be observed if the manager wants to estimate the mean assembly time within 0.25 minutes? Round to the nearest whole number.

• 829

• 29

• 415

• 58

Determine whether the action would increase or decrease the margin of error:

Increase the sample size

• Margin of error increases

• Margin of error decreases