The arithmetic mean is a commonly used measure of variability

One of the first teratogens to be recognized was German measles

Indicate whether this statement is true or false.

Assume a normal distribution of height scores, with a mean of 68" and a

standard deviation of 3", then a. 68% of the cases must fall between 65" and 71" b. 50% of the cases must fall below 68" c. 68% of the cases must fall at exactly 68" d. a and b, but not c