SOLUTION: According to records of commonwealth Edison, the mean electric consumption during January is 1,650 kilowatt hours, with a standard deviation of 320 kilowatt hours. The monthly

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Question 858772: According to records of commonwealth Edison, the mean electric consumption
during January is 1,650 kilowatt hours, with a standard deviation of 320
kilowatt hours. The monthly electric consumption for January follows a normal
distribution.
a. Selecting a customer at random, find the probability that the customer uses
less than 1,000 kilowatt hours in January.
b. Selecting a customer at random, find the probability than the customer uses
between 1,500 and 2,500 kilowatt hours in January.
c. Commonwealth Edison wants to identify its heaviest users, which are those
that are in the top 6% of electric consumption. How many kilowatt hours in
January would qualify for the heavy user classification?
Answer by psbhowmick(878) (Show Source):
You can put this solution on YOUR website!
a) Let the electric consumption be the random variable X and normally distributed with mean and standard deviation .

At first calculate the Z-score corresponding to 1000 kilowatt hours.

To find the probability that a house uses less than 1000 kilowatt hours of electricity:

Try the other parts yourself. If you still need help then contact me.
Cheers!!!