The physical plant at the main campus of a large state university recieves daily requests to replace florecent lightbulbs. The distribution of the number of daily requests is bell-shaped and has a mean of 48 and a standard deviation of 9. Using the empirical rule (as presented in the book), what is the approximate percentage of lightbulb replacement requests numbering between 48 and 66? Do not enter the percent symbol. ans = %