Assume that a sample is used to estimate a population proportion $\displaystyle \mu$. Find the margin of error E that corresponds to a sample of size 483 with a mean of 77.7 and a standard deviation of 11.7 at a confidence level of 98%.

Report $\displaystyle {E}$ accurate to one decimal place because the sample statistics are presented with this accuracy.
E =

Answer should be obtained without any preliminary rounding. However, the critical value may be rounded to 3 decimal places.