Suppose you have random variable that is normally distributed with a mean of 85 and a standard deviation of 5 units. You have an observed value x=56. Without performing any calculations. Would you expect the Z-score of this observed value to be?
a. The z-score that corresponds to this observed value is equal to zero.
b. Negative. This value is well below the mean.
c. Negative. The area under the curve is negative.
d. Positive The value is less than the mean but bigger than the standard deviation.