# The confidence interval for Random Samples

An experiment involves selecting a random sample of 256 middle managers for study. One item of interest is annual income. The sample mean is computed to be $35,420 and the sample standard deviation is $2,050. Using this information, calculate the 95% confidence interval (rounded to the nearest $10). Interpret your findings.

© BrainMass Inc. brainmass.com June 3, 2020, 7:05 pm ad1c9bdddfhttps://brainmass.com/statistics/confidence-interval/confidence-interval-random-samples-85545

#### Solution Preview

Hello

Please see the response as below

Sample mean of annual income, x(bar) = $35420

Sample standard deviation of the annual income, s = $2050

As we do not know the population standard deviation, the sample standard deviation is ...

#### Solution Summary

The solution contains calculation of the 95% confidence interval and interpretation of the result.

$2.19