Find the indicated probability.
-In one region, the September energy consumption levels for single-family homes are found to be normally distributed with a mean of 1050 kWh and a standard deviation of 218 kWh. For a randomly selected home, find
The probability that the September energy consumption level is between 1100 kWh and 1225 kWh.
A) 0.0910
B) 0.2881
C) 0.1971
D) 0.3791

Question

Quizplus · Accepted Answer

Using the normal distribution formula, we can calculate the z-scores for the given values:
z1 = (1100 - 1050) / 218 = 0.229
z2 = (1225 - 1050) / 218 = 0.804
Then, we can find the area under the standard normal distribution curve between these two z-scores using a standard normal distribution table or a calculator:
P(0.229 < z < 0.804) = 0.1971
Therefore, the probability that the September energy consumption level is between 1100 kWh and 1225 kWh is 0.1971, which corresponds to option C.

Find the Indicated Probability