posted by nicole on .
Assume that a set of test scores is normally distributed with a mean of 80 and a standard deviation of 25. Use the 68-95-99.7 rule to find the following quantities.
The percentage of scores less than 80 is?
Since 80 is the mean, the fraction le4ss than that is 50%. You don't need to invoke a 68-95-99.7 rule to figure that out. You also don't need to know the standard deviation.