The monthly amounts spent for food by families of four receiving food stamps approximates a symmetrical,normal distribution. The sample mean is $150 and the standard deviation is $20. Using the Empirical rule,about 95% of the monthly food expenditures are between what two amounts?
A)$100 and $200
B)$85 and $105
C)$205 and $220
D)$110 and $190

Question

Quizplus · Accepted Answer

According to the Empirical rule, approximately 95% of the data falls within 2 standard deviations of the mean.

So, the lower limit would be:

$150 - (2 * $20) = $110

And the upper limit would be:

$150 + (2 * $20) = $190

Therefore, the monthly food expenditures are between $110 and $190 for about 95% of the families of four receiving food stamps.

Choice A is too wide and would include more than 95% of the data.

Choice B is too narrow and would exclude more than 5% of the data.

Choice C is too high and would exclude more than 5% of the data.

The Monthly Amounts Spent for Food by Families of Four