Use the given information to find the minimum sample size required to estimate an unknown population mean μ.

How many business students must be randomly selected to estimate the mean monthly earnings of business students at one college? We want 95% confidence that the sample mean is within $140 of the population mean, and the population standard deviation is known to be $569.

The number of business students that must be randomly selected to estimate the mean monthly earnings of business students at one college is 64.

Step-by-step explanation:

The (1 - α) % confidence interval for population mean is:

The margin of error for this interval is:

The information provided is:

σ = $569

MOE = $140

Confidence level = 95%

α = 5%

Compute the critical value of z for α = 5% as follows:

*Use a z-table.

Compute the sample size required as follows:

Thus, the number of business students that must be randomly selected to estimate the mean monthly earnings of business students at one college is 64.

a. she will receive a refund of $278.

step-by-step explanation:

ou would have 12 of each