w8 Assignment

Week 8 Assignment – An Example

Three sororities took a random sample of five sisters regarding their grade points for the past term and the results are shown below.

Sorority A	Sorority B	Sorority C
2.17	2.63	2.63
1.85	1.77	3.78
2.83	3.25	4
1.69	1.86	2.55
3.33	2.21	2.45

In Excel, carry out an ANOVA to determine whether there is evidence to support the claim that the mean grade point was not the same between the three sororities. Test at the 0.05 level and at the 0.01 level.

Setup the null and alternative hypotheses.

Null Hypothesis: Ho: There is no difference in mean grade point between the three sororities.

Alternative Hypothesis: There is difference in mean grade point between the three sororities.

Level of Significance: 0.05 and 0.01 (given)

Open an Excel spreadsheet and enter data as shown below:

From the menubar, choose “Data Analysis”, and select Anova: Single Factor

Click OK.

Define the input range, choose Grouped By “Columns”, Check the box “Labels in the first row” and define the output range where you want the output created.

Click OK again to get the output below:

Anova: Single Factor
SUMMARY
Groups	Count	Sum	Average	Variance
Sorority A	5	11.87	2.374	0.47648
Sorority B	5	11.72	2.344	0.37108
Sorority C	5	15.41	3.082	0.55417
ANOVA
Source of Variation	SS	df	MS	F	P-value	F crit
Between Groups	1.74468	2	0.87234	1.866993	0.196814	3.885294
Within Groups	5.60692	12	0.467243
Total	7.3516	14

Now compare the p-value in the output above (highlighted in yellow) with levels of significance.

If p-value is less that the selected level of significance, reject the null hypothesis; Otherwise, there is no evidence to reject the null hypothesis.

In this example, we can see that p-value is greater than both levels of significance and therefore there is no evidence to reject the null hypothesis.

We can conclude there is no significant difference in the mean grade point between the three sororities.