6) The paralyzed Veterans of America is a philanthropic organization that relies on contributions. They send free mailing labels and greeting cards to potential donors on their list and ask for voluntary contribution. To test a new campaign, they recently sent letters to a random sample of 8,967 potential donors and received 4781 donations. a) Let p be the proportion of all donors that say they have contributed to the new campaign. Find a point estimate for p b) Find 90% confidence interval for population proportion. Interpret the results.