Question

Determine the probability (as a decimal rounded to the nearest hundredth) of a normal random variable with a mean of three and a standard deviation of four realizing a value that is strictly greater than 1.9

Answer 1

Explanation:

On a normal distribution table with z scores of 0 as the mean and the standard deviations going to the right and to the left, 1.9 on the normal curve where 3 is the mean falls at -.275 on the normal curve where 0 is the mean. I used the normal distribution z table for negative values to get that .39165 lies to the left of -.275, which means that 1 - .39165 of the data lies to the right.

The probability that the value is greater than 1.9 is .60835, or as a percentage, 60.835%.