01. A manager from a local pizzeria believes that the average delivery time is between 30 and 40 minutes. He wants to do a sampling study to estimate this time more accurately. From a small pilot sample, the standard deviation is estimated to be 2.23 minutes. He wants to find the sample size needed to achieve a maximum allowable sampling error of 0.20 minutes with 97.5 percent confidence. The proper sample size for the proposed work sampling study should be _____