A researcher is interested in testing the effects of different fertilizers. The researcher applied 5 different fertilizer formulas to three different types of seeds. The average number of days it took the seeds to grow 12 inches was recorded. The researcher will use a significance level of alpha = .05.
| | Fertilizer 1 | Fertilizer 2 | Fertilizer 3 | Fertilizer 4 | Fertilizer 5 |
| :--- | :--- | :--- | :--- | :--- | :--- |
| Seed A | 106 | 95 | 94 | 103 | 100 |
| Seed B | 110 | 98 | 11 | 108 | 105 |
| Seed C | 94 | 86 | 98 | 99 | 94 |
| Source of Variation | df | F | P-Value |
| :--- | :--- | :--- | :--- |
| Seed | 2 | 28.30 | 0.000008 |
| Fertilizer | 5 | 12.39 | 0.000119 |
| Interaction | 15 | 1.97 | 0.122090 |
a. Is there a significant difference in plant growth among the three seed types? If so, is a follow-up test needed for further investigation? Explain.
b. Is there a significant difference in growth among the different fertilizers? Explain. If so, is a follow-up test needed for further investigation? Explain.
c. Do the fertilizers affect the seed types differently? Explain your answer.