More bell curve questions

thespacecowboy · Jan 9, 2004

I have a list of employee appraisal scores, ranging from 2-5. 3 Should be the norm (average) score.
I would like to plot these to show 1) normal distribution around 3 and 2) curve if possible.

I've looked through the posts on here and also some of the linked webpages, but cannot quite fathom it out!

I've pasted my sheet so far, can someone tell me where I'm going wrong!

Test deviation.xls

A

B

C

D

E

F

1

Sumofscore

2

Score2

8

Average

3.38

3

2

StdDeviation

1.245

4

2

NormDist

0.382

5

2

6

2

7

2

8

2

9

2

10

2

11

Score3

6

12

3

13

3

14

3

15

3

16

3

17

3

18

Score4

3

19

4

20

4

21

4

22

Score5

7

23

5

24

5

25

5

26

5

27

5

28

5

29

5

Sheet1 (3)

Andrew Poulsom · Jan 9, 2004

Did you look here?

http://www.tushar-mehta.com/excel/charts/normal_distribution/index.htm

thespacecowboy · Jan 9, 2004

Yes I did thanks Andrew. It was all a little confusing for me though, I guess I should brush up on my maths a little!

I've understood the basics, but another reply on the board I trued to work through did unfortunately not advance my understanding.

Essentially I want to be able to plot the scores on a graph and show the distribution, which should give some kind of bell curve, although not a perfect one.

thanks

thespacecowboy · Jan 9, 2004

OK. I've worked through the example, and after some perseverance think I know where I'm going with this.
The enclosed is the example given on the webpage.
I have inputted the standad deviation and Mean from my list of values.
The graph given is a bell curve, but I'm not sure if the data in it is mine! if this makes sense!

I have a group of appraisal scores, such as 25 2's. 50 3's, 40 4's and 10 5's.

There are two things I want to do
1. Make sure the graph the below plots is actually mine
2. (additional). If we have 300 employees and I want a forced normal distribution, do I use standard percentages (i.e. 68% 1 deviation, 27% 2 deviations, 5% 3 deviations)?

This may be a bit mathematical, but hopefully someone can help!!

std deviation.xls