In: Statistics and Probability
Public safety officers are interested in how safe students feel when walking around campus late at night. They sample 20 students, asking them to rate their fear any number between 0 (no fear) and 10 (extreme fear). Below are their results:
1 0 2.5 5 3 7 4 5 6 5.5
6 2 1 0 3.5 5.5 5 3 4 3
A. What is the mean level of fear?
14. What is the standard deviation for their data? Show your calculations for full credit.
B. What is the median level of fear?
C. For participants with a score of 0, what is their z score? Show your calculations for full credit.
D. If the officers had a data point with a z score of 2.50, what would be the actual score? Show your calculations for full credit.
A) Given that, n= 20
Standard deviation formula is,
= 2.0622
B) For finding median we arrange observation in ascending order,
0 0 1 1 2 2.5 3 3 3 3.5 4 4 5 5 5 5.5 5.5 6 6 7
C ) Z score for x=0
= (0 - 3.6) / 2.0622 = - 1.7457
D)
= 2.50*2.0622 + 3.6
= 8.7555