statistics exam and the AP literature Exam. On the statistics test, the mean score was 2.4 with a standard deviation of .6. on the literature test the mean score was 2.65 with a standard deviation of .55. if you wanted to look at the combined scores( and assumed the tests were independent), what would their mean and standard deviation be?

5.05, 0.66
5.05, 1.15
5.05, 1.07
5.05, 0.82
5.05, 0.42

Question

statistics exam and the AP literature Exam. On the statistics test, the mean score was 2.4 with a standard deviation of .6. on the literature test the mean score was 2.65 with a standard deviation of .55. if you wanted to look at the combined scores( and assumed the tests were independent), what would their mean and standard deviation be?

5.05, 0.66
5.05, 1.15
5.05, 1.07
5.05, 0.82
5.05, 0.42

amistre64 · Answer

memorys a bit fussy, but I think variances add ... which would jsut be a distance formula since sd = sqrt(var)

sqrt( (sda)^2 + (sdb)^2)