Estimated Margin of Error

If the margin of error decreases, what happens to the required sample size?

• Remains the same

• Increases

• Decreases

• Fluctuates

A researcher wants to estimate the average height of students in a university with a margin of error of 0.05 meters and a 90% confidence level. If the population standard deviation is known to be 0.2 meters, what sample size is required?

• 26

• 27

• 44

• 43

A manufacturing company wants to estimate the mean time taken to assemble a product with a margin of error of 2 minutes and a 90% confidence level. If the standard deviation of assembly time is 10 minutes, how many units should be sampled?

• 68

• 67

• 42

• 41

If the confidence level is increased, what happens to the margin of error?

• Decreases

• Increases

• Remains the same

• Fluctuates

The amount added and subtracted to the statistic.

• Margin of Error

• Confidence Interval

• Z Score

• Population

The amount added and subtracted to the statistic.

• Margin of Error

• Point Estimator

• Statistic

• Population

Margin of error equals:

• Critical Value ∗ standard Error

• z*

• 1.96

• Standard Error

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

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

Which of the following correctly describes the relationship between sample size and margin of error?

• Increasing the sample size decreases the margin of error.

• Decreasing the sample size decreases the margin of error.

• Increasing the sample size increases the margin of error.

• The sample size has no effect on the margin of error.