Crop | ||||
Fertilizer | Corn | Wheat | Rice | Soy |
Blend A | 128 | 123 | 151 | 166 |
150 | 156 | 125 | 178 | |
174 | 112 | 117 | 187 | |
116 | 100 | 155 | 153 | |
109 | 168 | 158 | 195 | |
Blend B | 175 | 135 | 167 | 140 |
132 | 130 | 183 | 145 | |
120 | 176 | 142 | 159 | |
187 | 120 | 167 | 131 | |
184 | 155 | 168 | 126 | |
Blend C | 185 | 156 | 175 | 185 |
138 | 180 | 173 | 206 | |
178 | 147 | 154 | 188 | |
176 | 146 | 191 | 165 | |
190 | 193 | 169 | 188 |
A company has developed a new fertilizer to increase crop
production and wants to understand which of the three blends are
most effective for four types of crops (corn, wheat, rice, and
soy). They randomly test each of the three blends on five samples
of each of four types of crops and measure the crop yields.
Use the data listed above.
Complete the ANOVA table (2 decimal places)
a:
d:
b:
e:
c:
f:
g. Conduct the F-test for the interaction (at alpha=0.05). Can you reject the null hypothesis?
(yes/no):
h. Conduct the F-test for Fertilizer main effect (at alpha=0.05). Can you reject the null hypothesis?
(yes/no):
i. Conduct the F-test for Crop main effect (at alpha=0.05). Can you reject the null hypothesis?
(yes/no):
Anova: Two-Factor With Replication | ||||||
SUMMARY | Corn | Wheat | Rice | Soy | Total | |
Blend A | ||||||
Count | 5 | 5 | 5 | 5 | 20 | |
Sum | 677 | 659 | 706 | 879 | 2921 | |
Average | 135.4 | 131.8 | 141.2 | 176 | 146.05 | |
Variance | 707.8 | 844.2 | 354.2 | 279 | 782.37 | |
Blend B | ||||||
Count | 5 | 5 | 5 | 5 | 20 | |
Sum | 798 | 716 | 827 | 701 | 3042 | |
Average | 159.6 | 143.2 | 165.4 | 140 | 152.1 | |
Variance | 978.3 | 498.7 | 217.3 | 166 | 511.04 | |
Blend C | ||||||
Count | 5 | 5 | 5 | 5 | 20 | |
Sum | 867 | 822 | 862 | 932 | 3483 | |
Average | 173.4 | 164.4 | 172.4 | 186 | 174.15 | |
Variance | 422.8 | 443.3 | 175.8 | 212 | 329.5 | |
Total | ||||||
Count | 15 | 15 | 15 | 15 | ||
Sum | 2342 | 2197 | 2395 | 2512 | ||
Average | 156.1333 | 146.4667 | 159.667 | 167 | ||
Variance | 866.8381 | 705.8381 | 404.952 | 606 | ||
ANOVA | ||||||
Source of Variation | SS | df | MS | F | P-value | F crit |
Fertilizer (Sample) | 8749.43 | 2 | 4374.72 | 9.91 | 0.0003 | 3.19 |
Crop (Columns) | 3414.20 | 3 | 1138.07 | 2.58 | 0.0646 | 2.8 |
Interaction | 6224.70 | 6 | 1037.45 | 2.35 | 0.0454 | 2.29 |
Within | 21196.40 | 48 | 441.59 | |||
Total | 39584.73 | 59 |
g. Since P-value for interaction=0.0454<0.05 so we reject the null hypothesis. Option yes.
h. Since P-value for Fertilizer=0.0003<0.05 so we reject the null hypothesis. Option yes.
i. Since P-value for Crop=0.0646>0.05 so we fail to reject the null hypothesis. Option No.
Crop Fertilizer Corn Wheat Rice Soy Blend A 128 123 151 166 150 156 125 178...
data: (copy and paste in excel to view columns in alignment) Sample Repair Time (days) 1 12 2 17 3 9 4 16 5 10 6 18 7 12 8 14 9 15 10 14 11 14 12 8 13 11 14 10 15 8 16 8 17 14 18 12 19 14 20 13 21 12 22 15 23 15 24 10 25 24 26 17 27 13 28 15 29 13 30 15 31 36 32 40 33 ...