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 (.07) and its Z score. Insert Z score in equation above to find raw score.
the average yearly utility costs on Middleton is $1722 with stdev of 146. assume that the utility costs follow a normal distribution.
1) What would the utility costs have to be so that only 7% of houses in Middleton have utility costs greater than this amount
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