We have been given that a set of data with a mean of 45 and a standard deviation of 8.3 is normally distributed. We are asked to find the value that is +3 standard deviations away from the mean.
To find the value that is 3 standard deviation away from mean, we will multiply 3 by standard deviation and ad the result to mean.
Therefore, 69.9 is 3 standard deviation away from mean of or given data set and option D is the correct choice.
