SOLUTION: According to the records of an electric company serving the Boston area, the mean electric consumption for all households during winter is 1650 kilowatt-hours per month. Assume tha

Algebra ->  Probability-and-statistics -> SOLUTION: According to the records of an electric company serving the Boston area, the mean electric consumption for all households during winter is 1650 kilowatt-hours per month. Assume tha      Log On


   



Question 1171090: According to the records of an electric company serving the Boston area, the mean electric consumption for all households during winter is 1650 kilowatt-hours per month. Assume that the monthly electric consumptions during winter by all households in this area have a normal distribution with a mean of 1650 kilowatt-hours and a standard deviation of 320 kilowatt-hours. What percentage of the households in this area have a monthly electric consumption of 1858to1948 kilowatt-hours?
Round your answer to two decimal places.

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
This is z=(x-mean)/sd
z is between (1858-1650)/320 or 208/320 and (1948-1650)/320 or 298/320. That probability is 0.0820 or 8.20%.
Can also check on calculator 2nd VARS2(1858,1948,1650,350)ENTER for the same result.