A sample of the monthly amounts spent for food by families of four receiving food stamps approximates a symmetrical distribution. The sample mean is $150 and the standard deviation is $20. Using the Empirical Rule, about 95 percent 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
E) None of the choices are correct.

Question

Quizplus · Accepted Answer

The Empirical Rule states that for a symmetrical distribution, about 95% of the data falls within two standard deviations of the mean. In this case, the mean is $150 and the standard deviation is $20, so 95% of the data falls between $150 - 2($20) = $110 and $150 + 2($20) = $190.

A Sample of the Monthly Amounts Spent for Food by Families