Which of the following is not a characteristic of the normal

Which of the following is not a characteristic of the normal probability distribution?

a. The mean, median, and the mode are equal

b. The mean of the distribution can be negative, zero, or positive

c. The distribution is symmetrical

d. The standard deviation must be 1

Solution

d. The standard deviation must be 1

this is characteristic of standard normal curve, but may not be true in general