Which of the Following Is True Regarding the Standard Deviation

Multiple Choice

Which of the following is true regarding the standard deviation?

A) It indicates the degree of variation in the values in such a way as to be translatable into a normal curve.
B) One standard deviation above and below the midpoint in a normal distribution includes 68 percent of the area underneath the curve.
C) + or - 1.96 standard deviations above and below the midpoint in a normal distribution includes 95 percent of the area underneath the curve.
D) + or - 2.58 standard deviations above and below the midpoint in a normal distribution includes 99 percent of the area underneath the curve.
E) All of the above are correct.