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 ASorority BSorority C
2.172.632.63
1.851.773.78
2.833.254
1.691.862.55
3.332.212.45

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:

image1.png

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

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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
GroupsCountSumAverageVariance
Sorority A511.872.3740.47648
Sorority B511.722.3440.37108
Sorority C515.413.0820.55417
ANOVA
Source of VariationSSdfMSFP-valueF crit
Between Groups1.7446820.872341.8669930.1968143.885294
Within Groups5.60692120.467243
Total7.351614

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.