The number of students taking Scholastic Aptitude Test (SAT) has risen to all-time high of more than 1.5 million (College Board, August 26, 2008). Students are allowed to repeat test in hopes of enhancing the score that is sent to college as well as university admission offices. The number of times SAT was taken and number of students are as follows.
Number of Times Number of Students
1 721,769
2 601,325
3 166,736
4 22,299
5 6,730
Determine the Variance and Standard deviation for the number of times the SAT is taken (to 4 decimals)?