the number of students taking the SAT has risen to an alltim

the number of students taking the SAT has risen to an all-time high of more than 1.5 million (College Board, August 26, 2008). Students are allowed to repeat the test in hopes of improving the score that is sent to college and university admission offices. The number of times the SAT was taken and the number of students are as follows. a. Let x be a random variable indicating the number of times a student takes the SAT. Show the probability distribution for this random variable. Round your answers to four decimal places.

Solution

Might just be a rounding error. Here are my answers to 4 decimals using my TI-84 ...

SD = 0.7612
Var = 0.5794

I agree with your formula and your answers are so close to mine, but I did not round any of my calculations until the final results.

Hope that helps