Question: the per capita disposable income for residents of a us...

The per capita disposable income for residents of a U.S. city in a recent year is normally distributed, with a mean of about $44,000 and a standard deviation of about $2450. Use this information in Exercises 7-10.

7. Find the probability that the disposable income of a resident is more than $45,000. Is this an unusual event? Explain.

8. Out of 800 residents, about how many would you expect to have a disposable income of between $40,000 and $42,000?

9. Between what two values does the middle 60% of disposable incomes lie?

10. Random samples of size 8 are drawn from the population and the mean of each sample is determined. Is the sampling distribution of sample means normally distributed? Explain.