Construct a 95% confidence interval for the population mean. assume the population has a normal distribution. a sample of 20 college students had mean annual earnings of $3120 with a standard deviation of $677.

Given:
μ = $3120, population mean
σ = $677, population standard deviation.
The population is normally distributed.
n = 20, sample size.

At the 95% confidence level, the confidence interval is


1.96(σ/√n) = 1.96(677/√20) = 296.71
Th confidence interval for the mean is
($2823.29, $3416.71)

($2823.29, $3416.71)

24 students walk to school