What is the probability that someone selected at random

Question

Problem 1

1. The performances of a group of interns are evaluated by their supervisors at the end of their internships.

Their scores are: 55, 47, 62, 27, 50, 49, 66, 53, 50, 44, 63, 59.

Complete the calculations below using this data. Show all of your work and clearly label each of your calculations.

1. the mean
2. the median
3. the range
4. the standard deviation
5. the variance

Problem 2

The Anxiety General Stress Test (ANGST) has been designed to gauge the level of psychological stress management trainees experience when they are under pressure.

For a random sample of trainees the scores are as follows: 47, 49, 53, 53, 54, 58, 61, 64, 75, 81.

Complete the calculations below using this data. Show all of your work and clearly label each of your calculations.

1. What is the z score equivalent of ANGST = 81?
2. What is the probability that someone selected at random will score 81 or lower?
3. What percentage of all trainees will score between 60 and 75?