Confidence Intervals Review

Front

What is a confidence interval?

Back

A confidence interval is a range of values that is used to estimate the true value of a population parameter. It provides an interval of plausible values for the parameter.

Front

What does a confidence interval estimate?

Back

A confidence interval estimates a population parameter.

Front

Given the interval (1.2, 1.8), what is the point estimate?

Back

The point estimate is 1.5.

Front

Given the interval (1.2, 1.8), what is the margin of error?

Back

The margin of error is 0.3.

Front

How do you construct a confidence interval?

Back

To construct a confidence interval, you need the sample mean, the critical value (t* or z*), and the standard error of the mean.

Front

What is the formula for the margin of error in a confidence interval?

Back

Margin of Error = Critical Value * Standard Error.

Front

What is the critical value t* for a 90% confidence interval with n = 19?

Back

The critical value t* can be found using a t-distribution table or calculator.

Front

What happens to the confidence interval when the sample size increases?

Back

Increasing the sample size decreases the width of the confidence interval.

Front

What is the relationship between confidence level and the width of the confidence interval?

Back

As the confidence level increases, the width of the confidence interval also increases.

Front

What is the critical value t* for a 99% confidence interval with n = 12?

Back

The critical value t* is 3.106.