Homework SourseThe average weekly earnings of bus drivers in the city is 98
The average weekly earnings of bus drivers in the city is $980 with a standard deviation of $47. Assume that we select a random sample of 81 bus drivers. (a) Compute the standard error of the mean. (b) What is the probability that the sample mean will be greater than $985? (c) If the population of bus drivers consisted of 400 drivers, what would be the standard error of the mean?
The average weekly earnings of bus drivers in the city is $980 with a standard deviation of $47. Assume that we select a random sample of 81 bus drivers. (a) Compute the standard error of the mean. (b) What is the probability that the sample mean will be greater than $985? (c) If the population of bus drivers consisted of 400 drivers, what would be the standard error of the mean?
The average weekly earnings of bus drivers in the city is $980 with a standard deviation of $47. Assume that we select a random sample of 81 bus drivers. (a) Compute the standard error of the mean. (b) What is the probability that the sample mean will be greater than $985? (c) If the population of bus drivers consisted of 400 drivers, what would be the standard error of the mean?
The average weekly earnings of bus drivers in the city is $980 with a standard deviation of $47. Assume that we select a random sample of 81 bus drivers. (a) Compute the standard error of the mean. (b) What is the probability that the sample mean will be greater than $985? (c) If the population of bus drivers consisted of 400 drivers, what would be the standard error of the mean?
Solution
a.
Sx = s / sqrt(n) = 5.2222 [answer]
***********
b.
Using Excel,
P(greater than 985) =1 - NORMDIST(985, 980, 5.2222, 1)
= 0.169171 [answer]
************
c.
Sx = s / sqrt(n) = 47/sqrt(400) = 2.35 [answer]
