The average temperature in households is 67.6 degrees F. The standard deviation is 4.2 degrees F. A random sample of 51 households is to be selected

(a) What is the probability that the average of this sample will be above 68.3 degrees F?
Probability = (4 decimal places)

(b) What is the probability that the average of this sample will be within 1.2 DEGREES F of the population mean?
Probability = (4 decimal places)

(c) What is the probability that the average of this sample will be within 1.4 standard errors of the population mean?
Probability = (4 decimal places)

Z = (score-mean)/SEm(Standard Error of the mean)

SEm = SD/√(n-1)

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the Z scores.