The annual income of residents in a county is $42,000 with a standard deviation of $10,000. Under the assumption that the distribution of annual incomes is Normal, between what two values do 95% of the incomes of county residents lie?

Question

Quizplus · Accepted Answer

For a normal distribution, 95% of the data lies within approximately 2 standard deviations from the mean. The mean is $42,000 and the standard deviation is $10,000. Therefore, 2 standard deviations from the mean are $42,000 ± 2($10,000) = $42,000 ± $20,000, which gives us the range of $22,000 to $62,000.

The Annual Income of Residents in a County Is $42,000