A study was conducted to see if students’ writing skills continue to improve as the academic year progresses. English 101 students were asked to write essays throughout the year in September, December, March and June. The scores were compared to see if there is any improvement in this oneyear course. Was there a significant improvement?
The appropriate test for this problem is:
oneway ANOVA 
repeated measurements

The obtained statistic is:
F = 24.17 
F = 12.71 
F = 21.47 
F = 17.42 
The associated p value is:
< .05 
< .01 
< .001 
< .0001 
Decision is:
reject the null 
retain the null 
Conclusion is:
1) March scores are significantly lower than the rest of the months 
2) December scores are significantly higher than September scores 
3) March scores are significantly higher than September scores 
4) June scores are significantly higher than the rest of the months 
5 )no conclusion can be drawn 
Following is the output of one way ANOVA:
Anova: Single Factor  
SUMMARY  
Groups  Count  Sum  Average  Variance  
September  33  664  20.12121212  12.10984848  
December  33  649  19.66666667  10.04166667  
March  33  697  21.12121212  9.984848485  
June  33  837  25.36363636  5.863636364  
ANOVA  
Source of Variation  SS  df  MS  F  Pvalue  F crit 
Between Groups  670.3863636  3  223.4621212  23.52232855  3.43E12  2.675387 
Within Groups  1216  128  9.5  
Total  1886.386364  131 
The F test statistics is:
F = 23.52
The pvalue is less than 0.0001
pvalue < 0.0001
Reject null hypothesis.
5 )no conclusion can be drawn
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