Chapter 10: Q. 3.15 (page 702)

Mrs. Woods and Mrs. Bryan are avid vegetable gardeners. They use different fertilizers, and each claims that hers is the best fertilizer to use when growing tomatoes. Both agree to do a study using the weight of their tomatoes as the response variable. Each planted the same varieties of tomatoes on the same day and fertilized the plants on the same schedule throughout the growing season. At harvest time, each randomly selects $15$ tomatoes from her garden and weighs them. After performing a two-sample t test on the difference in mean weights of tomatoes, they get $t = 5.24$ and $P = 0.0008$ . Can the gardener with the larger mean claim that her fertilizer caused her tomatoes to be heavier?
a. Yes, because a different fertilizer was used on each garden.
b. Yes, because random samples were taken from each garden.
c. Yes, because the P-value is so small.
d. No, because the condition of the soil in the two gardens is a potential confounding variable.
e. No, because $15 < 30$

Short Answer

Expert verified

The correct answer is (d) No, because the condition of the soil in the two gardens is a potential confounding variable.

Step by step solution

Given information

We need to find that can the gardener with the larger mean claim that her fertilizer caused her tomatoes to be heavier

Explanation

Here , two of variable are confounded . Also we cant differentiate their effect on response variab;e

In this case, we examine that the soil conditions have been now now not taken into account, at the same time as the soil conditions may also need to have an impact at the burden of the tomatoes. Thus,soil conditions is a possible confounding variable.

Therefore, gardener with the bigger suggest can not declare that her fertilizer brought about her tomatoes to be heavier because soil conditions is a possible confounding variable.