Question

Please help me answer this question

Answer 1

9514 1404 393

Answer:

B. 3.5

Explanation:

The given range is 20 ± 7. The empirical rule tells you 95% of scores will fall within μ ± 2σ. We know μ = 20, so 2σ = 7. That is σ = 7/2 = 3.5.

The standard deviation is 3.5.