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)0.3791
B)0.0910
C)0.2881
D)0.1971

Question

Quizplus · Accepted Answer

To find the probability, calculate the z-scores for 1100 kWh and 1225 kWh, then find the probability between these z-scores using the standard normal distribution table. The z-score for 1100 kWh is (1100-1050)/218 ≈ 0.2294, and for 1225 kWh is (1225-1050)/218 ≈ 0.8028. The probability between these z-scores is approximately 0.1971.

In One Region, the September Energy Consumption Levels for Single-Family