3. A political candidate wants to estimate the mean income inher district. If the standard deviation for incomes is known to be$10,000, how large a sample must she take if she wishes to be 99%certain that her estimate is within $2000 of the true mean?
4. A company that manufactures golf clubs wants to estimate theproportion of golfers who are left-handed. How large a sample mustthey take if they want to be 90% certain that their estimate iswithin 6% of the true proportion?
