A population has a standard deviation of 50 A random sample of 100 items from this population is selected. The sample mean is determined to be 600. At 95% confidence, the margin of error is:. a. 5
b. 9.8
c. 650
d. 609.8

Step-by-step explanation:

The formula for calculating the margin of error is expressed as shown;

Margin of error = Z * S/√n

Z is the z-score at 95% confidence interval = 1.96

S is the standard deviation = 50

n is the sample size = 100

Substituting this values into the formula above;

Margin of error = 1.96 * 50/√100

Margin of error = 1.96 * 50/10

Margin of error = 1.96 * 5

Margin of error = 9.8

Hence the margin of error is 9.8

a. she will receive a refund of $278.

step-by-step explanation: