Does Age Effect Grade Point Average?

By Amanda Darrow and Dennis de Melo

Does age determine a higher or lower grade point average? By Using a

sample of 50 from the population of Salt Lake Community College

Students, we will determine if there is in fact a correlation between age

and G.P.A.

Collecting the Data

A questionnaire was handed out to 50 Salt Lake Community College Students.

The questionnaire asked two questions:• The participants age • The participants grade point average

Charts: Averages and SamplesAge Average G.P.A

18 2.6

19 2.5

20 2.9

21 2.8

22 2.7

23 3.1

24 3.1

25 3.9

26 2.7

28 3.3

29 3.4

30 2.8

31 3.3

33 3.7

35 2.6

36 3.7

38 3.2

39 4.0

42 3.9

Age (18-42)

Number of Samples

18-19 12

20-21 8

22-23 5

24-25 4

26-27 5

28-29 4

30-31 4

32-33 2

34-35 1

36-37 2

38-39 2

42 1

Grade Point Average Number of Samples

1.9 1

2.0 1

2.2 2

2.3 1

2.4 2

2.5 2

2.6 6

2.7 3

2.8 4

3.0 1

3.1 1

3.2 5

3.3 4

3.6 4

3.7 3

3.8 3

3.9 2

4.0 2

Age Statistics

• Mean: 23.5• Range: 42-18= 24• Mode= 19• Outliers: No Outliers

Age 5-Number Summary

• L=18 • Q1= 20 IQR: 29-20= 9 • µ= 23.5 Lower Fence:0-1.5(9) = 6.5• Q3= 29 Upper Fence: 29 + 1.5(9) =

42.5• H= 42

Age Standard Deviation18-19 = 12 12-4.2=7.8 7.8²= 60.84

20-21 = 8 8-4.2= 3.8 3.8²= 14.44

22-23 = 5 5-4.2= 0.8 0.8²= 0.64

24-25 = 4 4-4.2= -0.2 -0.2²= 0.04

25-27 = 5 5-4.2= 0.8 0.8²= 0.64

28-29 = 4 4-4.2= -0.2 -0.2²= 0.04

30-31 = 4 4-4.2= -0.2 -0.2²= 0.04

32-33 = 2 2-4.2= -2.2 -2.2²= 4.84

34-35 = 1 1-4.2= -3.2 -3.2²= 10.24

36-37 = 2 2-4.2= -2.2 -2.2²= 4.84

38-39 = 2 2-4.2= -2.2 -2.2²= 4.84

42 = 1 1-4.2= -3.2 -3.2²= 10.24

∑(x) = 50µx= 50/12= 4.2∑(X1-µ) = 111.68 111.68/12= 9.31√9.31 = 3.05

G.P.A. Statistics

• Mean: 3.1• Range: 4.0-2.5 = 1.5• Mode= 2.6, 2.7, 2.8, 3.1, 3.3, 3.7

and 3.9• Outliers: No Outliers

G.P.A. 5-Number Summary

• L=2.5• Q1= 2.75 IQR: 3.55-2.75= 0.8• µ= 3.1 LF: 2.75- 1.5(0.8) = 1.55• Q3= 3.55 UF: 3.55 + 1.5(0.8) = 4.75• H= 4.0

G.P.A Standard Deviation18-19 = 2.6 2.6-3.3=-0.7 -0.7²= 0.49

20-21 = 2.9 2.9-3.3=-0.4 -0.4²= 0.16

22-23 = 2.9 2.9-3.3=-0.4 -0.4²= 0.16

24-25 = 3.5 3.5-3.3=0.2 0.2²= 0.04

26-27 =2.7 2.7-3.3=-0.6 - 0.6²= 0.36

28-29 = 3.4 3.4-3.3=0.1 0.1²= 0.01

30-31 = 3.1 3.1-3.3=-0.2 -0.2²= 0.04

32-33 = 3.7 3.7-3.3=0.4 0.4²= 0.16

34-35 = 3.6 3.6-3.3=0.3 0.3²= 0.09

36-37 = 3.7 3.7-3.3=0.4 0.4²= 0.16

38-39 = 3.6 3.6-3.3=0.3 0.3²= 0.09

42 = 3.9 3.9-3.3=0.6 0.6²= 0.36

∑(x) = 39.6∑(X1-µ) = 2.12 µx=9.6/12=3.32.12/12= 0.177 √0.177= 0.421

Linear Correlation CoefficientAge Average G.P.A

18 2.6

19 2.5

20 2.9

21 2.8

22 2.7

23 3.1

24 3.1

25 3.9

26 2.7

28 3.3

29 3.4

30 2.8

31 3.3

33 3.7

35 2.6

36 3.7

38 3.2

39 4.0

42 3.9

Correlation:0.643159696N=19-1 = 18Table II:18 = 0.468

Since the final coefficient is smaller than the correlation we have a linear relation