In: Statistics and Probability
A factorial experiment involving two levels of factor A and three levels of factor B resulted in the following data.
Factor B | ||||
---|---|---|---|---|
Level 1 | Level 2 | Level 3 | ||
Factor A | Level 1 | 135 | 89 | 76 |
165 | 65 | 94 | ||
Level 2 | 125 | 128 | 119 | |
95 | 106 | 135 |
Test for any significant main effects and any interaction. Use α = 0.05.
Find the value of the test statistic for factor A. (Round your answer to two decimal places.)
Find the p-value for factor A. (Round your answer to three decimal places.)
p-value =
State your conclusion about factor A.
Because the p-value > α = 0.05, factor A is significant.Because the p-value ≤ α = 0.05, factor A is not significant. Because the p-value > α = 0.05, factor A is not significant.Because the p-value ≤ α = 0.05, factor A is significant.
Find the value of the test statistic for factor B. (Round your answer to two decimal places.)
Find the p-value for factor B. (Round your answer to three decimal places.)
p-value =
State your conclusion about factor B.
Because the p-value ≤ α = 0.05, factor B is significant.Because the p-value ≤ α = 0.05, factor B is not significant. Because the p-value > α = 0.05, factor B is significant.Because the p-value > α = 0.05, factor B is not significant.
Find the value of the test statistic for the interaction between factors A and B. (Round your answer to two decimal places.)
Find the p-value for the interaction between factors A and B. (Round your answer to three decimal places.)
p-value =
State your conclusion about the interaction between factors A and B.
Because the p-value ≤ α = 0.05, the interaction between factors A and B is not significant.Because the p-value > α = 0.05, the interaction between factors A and B is not significant. Because the p-value ≤ α = 0.05, the interaction between factors A and B is significant.Because the p-value > α = 0.05, the interaction between factors A and B is significant.
Let us construct an ANOVA to test various effectes:
Teh given data is
Factor B | ||||
Level1 | Level2 | Level3 | ||
Factor A | Level1 | 135 | 89 | 76 |
165 | 65 | 94 | ||
Total | 300 | 154 | 170 | |
Level2 | 125 | 128 | 119 | |
95 | 106 | 135 | ||
Total | 220 | 234 | 254 |
We have a 2X3 factorial experiments with 2 replivations each.
We shall foolow the following steps:
Let us denote by as the observation from the replicate of the level of afctor A and level of Factor B.
1. Calculate the correction factor:
2. The total sum of squares :
We shall form a table of squares and add them to get the sum of squares:
18225 | 7921 | 5776 | |
27225 | 4225 | 8836 | |
15625 | 16384 | 14161 | |
9025 | 11236 | 18225 | 156864 |
3. Sum of squares due to factor A:
4. Sum of squares due to Factor B:
5. Sum of squares due to table
Level1 | Level2 | Level3 | Total | |
Level1 | 300 | 154 | 170 | 624 |
Level2 | 220 | 234 | 254 | 708 |
Total | 520 | 388 | 424 | 1332 |
Level1 | Level2 | Level3 | Total | |
Level1 | 90000 | 23716 | 28900 | 142616 |
Level2 | 48400 | 54756 | 64516 | 167672 |
Total | 138400 | 78472 | 93416 | 310288 |
6. The interaction SS
7. Error SS
ANOVA Table:
Source | df | SS | MS | F | Critical F |
Main Effect A | 1 | 588 | 588 | 2.0512 | 5.9874 |
Main Effect B | 2 | 2328 | 1164 | 4.0605 | 5.1433 |
Interaction AXB | 2 | 4376 | 2188 | 7.6325 | 5.1433 |
Error | 6 | 1720 | 286.6667 | ||
Total | 11 |
Find the value of the test statistic for factor A. 2.05
Find the p-value for factor A. (Round your answer to three decimal places.)
p-value = 0.202
State your conclusion about factor A.
Because the p-value > α = 0.05, factor A is not significant.
Find the value of the test statistic for factor B. 4.06
Find the p-value for factor B. (Round your answer to three decimal places.)
p-value =0.077
State your conclusion about factor B.
Because the p-value > α = 0.05, factor B is not significant.
Find the value of the test statistic for the interaction between factors A and B. 7.63
Find the p-value for the interaction between factors A and B.
p-value =0.023
State your conclusion about the interaction between factors A and B.
Because the p-value ≤ α = 0.05, the interaction between factors A and B is significant.