Confidence Intervals

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, with a certain level of confidence.

Front

What does a 99% confidence level indicate?

Back

A 99% confidence level indicates that if we were to take 100 different samples and compute a confidence interval for each sample, approximately 99 of the intervals would contain the population mean.

Front

What is the z-value for a 95% confidence level?

Back

The z-value for a 95% confidence level is approximately 1.96.

Front

How do you calculate the margin of error in a confidence interval?

Back

The margin of error is calculated by multiplying the z-value by the standard error of the sample.

Front

What is the formula for a confidence interval for a population mean?

Back

The formula is: Confidence Interval = sample mean ± (z-value * standard error).

Front

What does the symbol 'n' represent in statistics?

Back

The symbol 'n' represents the sample size.

Front

What is the difference between a population and a sample?

Back

A population includes all members of a specified group, while a sample is a subset of the population used to represent the group.

Front

What is the significance of the margin of error in a confidence interval?

Back

The margin of error indicates the range of uncertainty around the sample estimate, affecting the width of the confidence interval.

Front

What is a common confidence level used in research?

Back

Common confidence levels used in research are 90%, 95%, and 99%.

Front

What is the impact of increasing the sample size on the confidence interval?

Back

Increasing the sample size generally decreases the width of the confidence interval, leading to a more precise estimate of the population parameter.