Suppose that the average time an employee takes to reach the
Suppose that the average time an employee takes to reach the office is 35 minutes. To address the issue of late comers, the mode of transport chosen by the employee is tracked: private transport (two-wheelers and four-wheelers) and public transport. The data on the average time (in minutes) taken using both a private transportation system and a public transportation system for a sample of employees are given below:
Private Transport
Public Transport
27
30
33
29
28
25
32
20
20
27
34
32
30
37
28
38
18
21
29
35
a. Considering the travel times (in minutes) of employees using private transport. Compute the z-score for the tenth employee with travel time of 29 minutes.
b. Considering the travel times (in minutes) of employees using public transport. Compute the z-score for the second employee with travel time of 29 minutes. How does this z-score compare with the z-score you calculated for part a?
c. Based on z-scores, do the data for employees using private transport and public transport contain any outliers? Show all work to support your answer.
| Private Transport | Public Transport |
| 27 | 30 |
| 33 | 29 |
| 28 | 25 |
| 32 | 20 |
| 20 | 27 |
| 34 | 32 |
| 30 | 37 |
| 28 | 38 |
| 18 | 21 |
| 29 | 35 |
Solution
to check the z score we have to find the mean and the standard deviation of both the groups seperately
private transport
mean = sum of all / total number = 279/10 = 27.9
standard deviation =
hence standard dev = 5.23
A) z score = (29 - 27.9)/5.23 = 0.21
z score = 0.5832
b) public transport
mean = 294/10 = 29.4
standard dev = 6.27
z score = (29-29.4)/6.27 = -0.06
z score = 0.5239
c) outlier is the number which is too deviation either high or low fromthe rest numbers
in private the number is 18
in public no outlier,

