Compute an ANOVA with statistical software or manually and u
Compute an ANOVA with statistical software (or manually), and use the .05 significance level to answer the following questions.
a. Is there a difference in the Size means?
b. Is there a difference in the Weight means?
c. Is there a significant interaction between Weight and Size?
Size
Small Medium Large
Weight Heavy 23 20 11
21 32 20
25 26 20
Light 13 20 11
32 17 23
17 15
8
Solution
We will use minitab software to Answer this question.
The ANOVA table for this question is
Source DF SS MS F P
weight 1 98.000 98.0000 2.48 0.141
size 2 156.333 78.1667 1.98 0.180
Interaction 2 36.333 18.1667 0.46 0.642
Error 12 473.333 39.4444
Total 17 764.000
Here we will make decision about question a,b and c through the p-value given in the table
a) The p-value for difference in the Size is 0.141 >0.05 then we are fail to rehect Hypothesis that all sizes are equal. Hence we claim that all effect of size are same.
b) The p-value for difference in the Weight is 0.180 >0.05 then we are fail to rehect Hypothesis that all weights are equal. Hence we claim that all effect of weight are same.
c) The p-value for significant interaction between Weight and Size is 0.642>0.05 then we are fail to rehect Hypothesis that there is no interaction between sizes and weights. Hence we claim that all effect of nteraction between sizes and weights is zero.
