Margin of Error

Front

What is the margin of error?

Back

The margin of error is a statistic that expresses the amount of random sampling error in a survey's results. It represents the range within which the true population parameter is expected to fall.

Front

How does increasing the confidence level affect the margin of error?

Back

Increasing the confidence level from 95% to 99.7% increases the margin of error because a higher confidence level requires a wider interval to ensure that the true parameter is captured.

Front

What is the formula for calculating the standard error of the mean?

Back

Front

If a sample has a standard deviation of 0.2 oz and a sample size of 40, what is the standard error?

Back

Front

How do you calculate the percentage of respondents who preferred a candidate in a survey?

Back

To calculate the percentage, divide the number of respondents who preferred the candidate by the total number of respondents and multiply by 100.

Front

In a survey of 120 voters, if 66 preferred Candidate A, what percentage preferred Candidate A?

Back

Front

What happens to the margin of error when the confidence level is decreased?

Back

Decreasing the confidence level from 95% to 68% decreases the margin of error because a lower confidence level requires a narrower interval.

Front

What is a confidence interval?

Back

A confidence interval is a range of values, derived from a data set, that is likely to contain the value of an unknown population parameter.

Front

If a confidence interval for a study is between $44 and $56, what is the average of the sample?

Back

The average of the sample is the midpoint of the confidence interval, which is $50.

Front

What is the relationship between sample size and margin of error?

Back

As the sample size increases, the margin of error decreases because larger samples provide more accurate estimates of the population parameter.