A normal distribution has a mean of µ = 40 with σ = 10.If a vertical line is drawn through the distribution at X = 35,what proportion of the scores are on the left side of the line?
A)0.3085
B)0.6915
C)0.0668
D)0.9332

Question

Quizplus · Accepted Answer

To find the proportion of scores on the left side of X = 35, we need to calculate the area under the normal distribution curve to the left of X = 35. We can use a standard normal distribution table or a calculator to find this area. Using a calculator, we can standardize X = 35 as (35-40)/10 = -0.5 and find the area to the left of -0.5 in the standard normal distribution table, which is 0.3085. Therefore, the proportion of scores on the left side of X = 35 in the normal distribution with mean 40 and standard deviation 10 is 0.3085 or 30.85%.

A Normal Distribution Has a Mean of µ = 40