In one region in the Bay Area, the September energy consumption levels for single-family homes are found to be normally distributed with a mean of 1050 kWh (kilowatts) and a standard deviation of 245 kWh.
a) For a randomly selected home, find the probability that theeptember energy consumption level is between 1100 kWh and 1225 kWh
. b) For a randomly selected home, find the probability that the September energy consumption level exceeds 1220 kWh.
c) In this distribution, find the number of kWh that separates the top 55% from the bottom 45%.
d) Suppose 30 homes have been randomly selected as a sample. Find the probability that the sample mean is less that 1100 kWh.
