Question

Between two negative z scores there must always be:

a. fewer than 50% of the cases

b. more than 50% of the cases

c. Exactly 50% of the cases

d. none of these, since 0% must always fall between negative z scores

I believe the correct answer is "A" though I am not sure why.

Answer 1

Ans: a. fewer than 50% of the cases

z scores can vary from - to . The z score corresponding to the mean is 0.

Since the standard normal distribution is symmetric about the mean, of the remaining scores, half is negative and half is positive. This means, less than half of the total values have negative z score. Therefore, there can never be 50% or more values between two negative z scores.