The accounting firm of Price Waterhouse annually monitors the U.S. Postal Service's performance. One parameter of interest is the percentage of mail delivered on time. In a sample of 332,000 items mailed between Dec. 10 and Mar. 3-the most difficult delivery season due to bad weather and holidays-Price Waterhouse determined that 282,200 items were delivered on time (Tampa Tribune, Mar. 26,1995). Use this information to estimate with 99%

confidence the true percentage of items delivered on time by the US. Postal Service. Interpret the result.