The average daily high temperatures in Lawton are approximately normally distributed with a mean of 58 degrees and a standard deviation of 12 degrees. Find the probabilities below:

The probability that the high would not exceed 65 degrees on any one day.

The probability that the average high for 7 randomly chosen days would be over 65 degrees.

1 answer

1. Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score.

2. Z = (score-mean)/SEm

SEm = SD/√n

Use same table.