Professor Sprout is researching the impact of using different fertilizers on plant growth. She wants to control for type of plant, so she tests 8 pairs of plants of the same type. She gives one plant in each pair fertilizer A and the other plant fertilizer B. She thinks that there will be a difference in the growth of the plants, but she is not sure which will be better. She finds that when she compares plant growth, Dbar = 8.04 and the variance is S²_D= 79.22. Plants given fertilizer A grew to 13cm while plants given fertilizer B grew to 8cm. Use alpha of .05.

1. Which type of t-test is this?

2. What are you degrees of freedom?

3. What is your t-critical?

4. What is your t-obtained?

5. What is your conclusion with statistical evidence? Do you reject or fail to reject the null hypothesis?