Question

A normal distribution has a mean of 75 and a standard deviation of 10 use the standard normal table to find the probability that a randomly selected X value from the distribution is less than or equal to 50

A. -2.5
B. 0.0062
C. 0.9938
D. 2.5

Answer 1

0.006

Explanation:

We are actually looking for the area under the standard normal curve to the left of 50. The proper distribution function on my old TI calculator is normalcdf(:

normalcdf(-1000,50,75, 10),

which returns 0.006 (Answer B)