The statistics course I'm taking is a technology based course, & goes hand in hand with the ti-83. I happened to have a ti-86 & need some help. I understand how to calculate the mean by hand & by the calculator for most circumstances. What I don't is when there are classes, for example Class Frequency 10-19 8 20-29 16 30-39 21 40-49 11 50-59 4 Now, I can compute the approximate mean by hand with the formula in the book. The answer gives a mean = 32.83 & a standard deviation = 11.06. The answer checks with the back of the book. How can I place this information into the ti-86 & get the same results?