SOLUTION: 9. A normal distribution of utility bills shows the mean to be $100 and the standard deviation of $12.
a) What percent of the utility bills are more than $125.
b) If 300 utilit
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-> SOLUTION: 9. A normal distribution of utility bills shows the mean to be $100 and the standard deviation of $12.
a) What percent of the utility bills are more than $125.
b) If 300 utilit
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Question 1120867: 9. A normal distribution of utility bills shows the mean to be $100 and the standard deviation of $12.
a) What percent of the utility bills are more than $125.
b) If 300 utility bills are randomly selected, about how many of them would you expect to be less than $90?
You can put this solution on YOUR website! z=(x-mean)/sd or 25/12 or +2.167
probability z>2.17 is 0.0150
for 300 bills, this would be 300*0.015 or 4.5. Four or five bills.
