A set of data is normally distributed with a mean of 455 and a standard deviation of 25. What percent of the data is in the interval 405–455? Answer is47.75% but idk how to do it :\

Question

A set of data is normally distributed with a mean of 455 and a standard deviation of 25. What percent of the data is in the interval 405–455? Answer is47.75%  but idk how to do it :\

anonymous · Answer

mean is 455. standard deviation is 25
you are asked for the percent between 405 and 455 in other words two standard deviations below the mean up to the mean
you need to look at a table for this to find the percent in that range
or else you can do the following:
know that $95.5\%$ the data is within two standard deviations of the mean, on BOTH sides
since you are only looking at one side, two standard deviations below the mean, it is half of that

anonymous · Answer

what do you mean  two standard deviations below the mean up to the mean? and idk how you got 95.5%...