The class mean score on a test was 60, and the standard deviation was 10. If Jack's score was within 2 standard deviations of the mean, what is the lowest score he could have received?
Choose the correct choice from the following options.
A) 30
B) 31
C) 45
D) 90
E) 20

Rationale: 1 sd from the mean is adding and subtrating the amount if standard deviation from the mean one time . 2 sd from the mean is adding and subtracting twice . 1 sd from the mean ranges from 70 to 50 , where 70 is within sd above the mean and 50 within 1 sd below the mean 2 sd = 10 twice = 20 from the the mean , which is 80 to 40 , where 80 is within 2 sd above the mean and 20 is within 2 sd below the mean . answer = e
Answer: E