Question

For a normal population with a mean of 0 and a variance 100, the P(X ≤ 0) is ___.

Answer 1

• For a normal population with a mean of 0 and a variance 100, the P(X ≤ 0) is 0.5.
• Explanation : mean is location , and variance is squared scale parameter for normal distribution , so the population is a normal with mean zero and a very long equal tail due to large variance , now since it is normal i.e symmetric its mean = median = mode , since its median is same as mean so median =0 and we know median divides the probability in 0.5:0.5 so the area of X , less than 0 is 0.5