A recent survey was conducted to compare the cost of solar energy to the cost of gas or electric energy. Results of the survey revealed that the distribution of the amount of the monthly utility bill of a 3-bedroom house using gas or electric energy had a mean of $104 and a standard deviation of $10. If the distribution can be considered mound-shaped and symmetric, what percentage of homes will have a monthly utility bill of more than $94?
A) approximately 95%
B) approximately 34%
C) approximately 16%
D) approximately 84%

Question

Quizplus · Accepted Answer

Since the distribution is mound-shaped and symmetric, it follows a normal distribution. A bill of $94 is one standard deviation below the mean ($104 - $10 = $94). According to the empirical rule, approximately 68% of data falls within one standard deviation of the mean, leaving 16% below one standard deviation below the mean. Therefore, approximately 84% of homes will have a bill more than $94.

A Recent Survey Was Conducted to Compare the Cost of Solar