Question

The mean annual income for people in a certain city is 40, with a standard deviation of 32. A pollster draws a sample of 38 people to interview. What is the probability that the sample mean income is less than 42 (thousands of dollars)?

Answer 1

The probability that the sample mean income is less than 42 (thousands of dollars) is 0.7944. This is calculated using the Z-score formula, where Z = (42 - 40)/32 = 0.0625. The Z-score is then used to find the probability using a Z-table.