Author Question: The average weekly earnings of bus drivers in a city are 950 (that is ) with a standard deviation of ... (Read 272 times)

KWilfred · **on:** Jun 24, 2018

The average weekly earnings of bus drivers in a city are 950 (that is ) with a standard deviation of 45 (that is ). Assume that we select a random sample of 81 bus drivers.
a. Assume the number of bus drivers in the city is large compared to the sample size. Compute the standard error of the mean.
b. What is the probability that the sample mean will be greater than 960?
c. If the population of bus drivers consisted of 400 drivers, what would be the standard error of the mean?

Question 2

Which of the following is NOT a characteristic of the normal probability distribution?
a. The graph of the curve is the shape of a rectangle.
b. The total area under the curve is always equal to 1.
c. The random variable assumes a value within plus or minus three standard deviations of its mean 99.72 of the time.
d. The mean is equal to the median, which is also equal to the mode.