Rich's first psychology exam score is +1 standard deviation from the mean in a normal distribution.The test has a mean of 60 and a standard deviation of 6.Rich's percentile rank would be approximately
A)70%.
B)84%.
C)66%.
D)cannot determine from the information given

Question

Quizplus · Accepted Answer

To find Rich's percentile rank, we need to find the area under the normal distribution curve to the left of his score. First, we need to standardize his score using the formula z = (x - mean) / standard deviation.

z = (x - 60) / 6 = 1

Using a standard normal distribution table or calculator, we can find that the area to the left of z = 1 is approximately 0.84. This means that approximately 84% of scores fall below Rich's score. Therefore, Rich's percentile rank would be approximately 84%.

Therefore, the correct choice is B.

Rich's First Psychology Exam Score Is +1 Standard Deviation from the Mean