Determine the minimum sample size required when you want to be 98% confident that the sample mean is within two units of the population mean. Assume a population standard deviation of 7.55 in a normally distributed population.

Answer: n = 78

Therefore, Determine the minimum sample size required when you want to be 98% confident that the sample mean is within two units of the population mean is 78

n > / = 78

Step-by-step explanation:

Given;

Standard deviation r = 7.55

Margin of error E = 2.0

Confidence interval of 98%

Z at 98% = 2.33

Margin of error E = Z (r/√n)

Making n the subject of formula, we have

n = (Z*r/E) ^2

n = (2.33 * 7.55/2.0) ^2

n = (8.79575) ^2

n = 77.3652180625

n > / = 78

Therefore, Determine the minimum sample size required when you want to be 98% confident that the sample mean is within two units of the population mean is 78