When mrs. myles gave a test, the scores were normally distributed with a mean of 72 and a standard deviation of 8. this means that 95% of her students scored between which two scores?

The empirical rule states that in a normal distribution,
68% of data is within 1 std deviation of the mean
95%  of data is within 2 std deviation of the mean
99.7% of data is within 3 std deviation of the mean

In this case 95% of the cases would be within two std deviations of the mean 
    mean - 8         and    mean + 8
     72   - 8 = 64   and    72 + 8 = 80 

then 95% of the scores are between  64% and 80% on the test. 

555%=6786666vgggcccf

Yes, that is the correct formula. to solve this problem given the number of years, plug in the number of years for t and plug the whole thing into the