Question

All of the following statements about the standard normal probability distribution are true EXCEPT: a) the expected value is 0 b) the total area under the standard normal curve is 1 c) the standard deviation can assume any positive value d) the probability that z assumes values between -1 and 1 is 0.6826

Answer 1

d) the probability that z assumes values between -1 and 1 is 0.6826.

Explanation:

In a standard normal probability distribution, the Z-value depends on the data set, the mean and the standard deviation, that means, it's a variable measure, it's not a constant, that's why the choice d is wrong.

On the other hand, the other choices are correct regarding standard normal probability distribution.

Therefore, the right answer is d.