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?

Answer 1

The answer is B: The probability is equal to p%.

Answer 2

The correct answer is:

The probability is equal to p%.

Step-by-step explanation:

In a normal curve, z would be a given distance above the mean. The probability that a variable is greater than or equal to z is given as p%. This represents the distance from z to the end of the curve.

-z, on the other hand, would be below the mean. The probability that a variable is less than or equal to -z would be the distance from -z to the end of the curve. Since a normal distribution curve is symmetric, this probability will also be p%.