The registrar at a local college has recorded the number of students who have dr
ID: 2946489 • Letter: T
Question
The registrar at a local college has recorded the number of students who have dropped a statistics class for each trimester. The length of one trimester is four months. The given data show the number of students who dropped the class over the last three years.
Class
Year
Semester
Dropped
Class
Year
Semester
Dropped
1
2010
Spring
5
6
2011
Fall
9
2
2010
Summer
3
7
2012
Spring
6
3
2010
Fall
7
8
2012
Summer
4
4
2011
Spring
5
9
2012
Fall
11
5
2011
Summer
4
What is
the
seasonal factor for the Spring? semester?
A.
0.9424
B.
1.2268
C.
0.6127
D.
1.4143
Class
Year
Semester
Dropped
Class
Year
Semester
Dropped
1
2010
Spring
5
6
2011
Fall
9
2
2010
Summer
3
7
2012
Spring
6
3
2010
Fall
7
8
2012
Summer
4
4
2011
Spring
5
9
2012
Fall
11
5
2011
Summer
4
Explanation / Answer
Solution:
Option A is correct.
We find the average of 2010, 2011 and 2012
Seasonal index for spring
2010 = Actual value/Average of 2010 = 5/5 = 1
2011 = 5/6 = 0.8333
2012 = 6/7 = 0.8571
Seasonal index = (1 + 0.8333 + 0.8571)/3 = 0.9424
2010 2011 2012 Average Spring 5 5 6 5.333333 Summer 3 4 4 3.666667 Fall 7 9 11 9 Average 5 6 7