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Chapter 10: Q. 11 (page 668)

Corn variety 1 yielded 140 bushels per acre last year at a research farm. This year, corn variety 2, planted in the same location, yielded only 110 bushels per acre. Unfortunately, we don鈥檛 know whether the difference is due to the superiority of variety 1 or to the effect of this year鈥檚 drought. This is an example of

(a) bias due to voluntary response.

(b) confounding.

(c) lack of blinding.

(d) sampling variability.

(e) the placebo effect.

Short Answer

Expert verified

The answer is option (b) confounding.

Step by step solution

01

Given Information

Corn variety 1 yielded 140 bushels per acre last year. And, corn variety 2, planted in the same location, yielded only 110 bushels per acre.

02

Explanation

Since we don't know whether the difference in bushels per year is due to the superiority of variety 1 or the effect of a year's drought.

Two variables are confounded when their effects on a response variable cannot be distinguished from each other. In this case, we cannot differentiate between the effect of the variables of variety and weather, which implies that this is an example of confounding.

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