According to the Internal Revenue Service, income tax returns one year averaged $1,332 in refunds for taxpayers with a standard deviation of $725. Assume that a negative refund means that the taxpayer owed money to the government.
a) What proportion of tax returns show a refund greater than $2,000?
b) What proportion of the tax returns show that the taxpayer owes money to the government?
c) What proportion of the tax returns show a refund between $100 and $700?