In: Statistics and Probability
Krusskal – Wallis Test Forty-minute workouts of one if the following activities three days a week will lead to a loss weight. The following sample data show the number of calories burned during 40-minute workouts for three different activities.
| 
 Swimming  | 
 Tennis  | 
 Cycling  | 
| 
 408  | 
 415  | 
 385  | 
| 
 380  | 
 485  | 
 250  | 
| 
 425  | 
 450  | 
 295  | 
| 
 400  | 
 420  | 
 402  | 
| 
 427  | 
 530  | 
 268  | 
a. At the 0.05 level of significance, is there evidence of a significant difference in the median amount of calories burned among the different activities?
b. What is your conclusion?
(a)
Ho: There is no significant difference between the median amount of calories
Ha: There is a significant difference between the median amount of calories
| 
 Calories  | 
 Group  | 
 Rank  | 
| 
 250  | 
 Cycling  | 
 1  | 
| 
 268  | 
 Cycling  | 
 2  | 
| 
 295  | 
 Cycling  | 
 3  | 
| 
 380  | 
 Swimming  | 
 4  | 
| 
 385  | 
 Cycling  | 
 5  | 
| 
 400  | 
 Swimming  | 
 6  | 
| 
 402  | 
 Cycling  | 
 7  | 
| 
 408  | 
 Swimming  | 
 8  | 
| 
 415  | 
 Tennis  | 
 9  | 
| 
 420  | 
 Tennis  | 
 10  | 
| 
 425  | 
 Swimming  | 
 11  | 
| 
 427  | 
 Swimming  | 
 12  | 
| 
 450  | 
 Tennis  | 
 13  | 
| 
 485  | 
 Tennis  | 
 14  | 
| 
 530  | 
 Tennis  | 
 15  | 
| 
 Sum of ranks:  | 
|
| 
 Swimming  | 
 41  | 
| 
 Tennis  | 
 61  | 
| 
 Cycling  | 
 18  | 

H = [12/{15(15 + 1)] [(41^2)/5 + (61^2)/5 + (18^2)/5] – 3(15 + 1) = 9.26
Critical χ2 value (Df = 2) = 5.9915
Since 9.26 > 5.9915, we reject Ho
(b)
There is a significant difference between the median amount of calories
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