Solution:
In excel get the mean and standard deviation
Data>Data analysis>Descriptive statistics
we get
Without Wait-Tracking System |
|
With-WaitTracking System |
|
|
|
|
|
Mean |
27.8 |
Mean |
15.5 |
Standard
Deviation |
16.03329868 |
Standard
Deviation |
9.489761 |
Sum |
278 |
Sum |
155 |
Count |
10 |
Count |
10 |
Solution(a)
z=x-mean/sd
z=30-27.8/16.03329868
z=0.14
z score=0.14
Solution(b)
z=x-mean/sd
z=30-15.5/9.489761
z=14.5/9.489761
z= 1.527963
z=1.53
z score=1.53
z score for with wait tracking system is high compared to z
score for without wait tracking system.
Solution(b)
with z score we can find outliers using z scores
outliers <-3 or outlier above 3
Without Wait-Tracking System |
mean |
stddev |
X-mean |
Z-x-mean/sd |
24 |
27.8 |
16.0333 |
-3.8 |
-0.23701 |
60 |
27.8 |
16.0333 |
32.2 |
2.00832 |
10 |
27.8 |
16.0333 |
-17.8 |
-1.11019 |
22 |
27.8 |
16.0333 |
-5.8 |
-0.36175 |
34 |
27.8 |
16.0333 |
6.2 |
0.386695 |
47 |
27.8 |
16.0333 |
19.2 |
1.197508 |
12 |
27.8 |
16.0333 |
-15.8 |
-0.98545 |
12 |
27.8 |
16.0333 |
-15.8 |
-0.98545 |
27 |
27.8 |
16.0333 |
-0.8 |
-0.0499 |
30 |
27.8 |
16.0333 |
2.2 |
0.137214 |
With-WaitTracking System |
Mean |
Standard deviation |
X-mean |
z=x-mean/sd |
14 |
15.5 |
9.489761 |
-1.5 |
-0.15807 |
9 |
15.5 |
9.489761 |
-6.5 |
-0.68495 |
33 |
15.5 |
9.489761 |
17.5 |
1.844093 |
10 |
15.5 |
9.489761 |
-5.5 |
-0.57957 |
18 |
15.5 |
9.489761 |
2.5 |
0.263442 |
30 |
15.5 |
9.489761 |
14.5 |
1.527963 |
12 |
15.5 |
9.489761 |
-3.5 |
-0.36882 |
17 |
15.5 |
9.489761 |
1.5 |
0.158065 |
9 |
15.5 |
9.489761 |
-6.5 |
-0.68495 |
3 |
15.5 |
9.489761 |
-12.5 |
-1.31721 |
no outliers for offices without a wait-tracking
system as no z value is below -3 or above 3
no outliers for offices with a wait-tracking system
as no z value is below -3 or above 3