Question

The probability that a random variable is greater than or equal to z standard deviations from the mean in a standard normal distribution is p%. What can be said with certainty about the probability that the random variable is less than or equal to –z standard deviations from the mean?
The probability is less than p%.
The probability is equal to p%.
The probability is greater than p%.
The probability is not equal to p%.

Answer 1

$$\Large P( Z \geq z ) = p\% $$