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Chapter 4: Q AP1.5. (page 276)

For a biology project, you measure the weight in grams (g) and the tail length in millimeters (mm) of a group of mice. The equation of the least-squares line for predicting tail length from weight is predicted taillength=20+3×weight

Which of the following is not correct?

(a) The slope is 3, which indicates that a mouse’s weight should increase by about3 grams for each additional millimeter of tail length.

(b) The predicted tail length of a mouse that weighs 38 grams is 134 millimeters.

(c) By looking at the equation of the least-squares line, you can see that the correlation between weight and tail length is positive.

(d) If you had measured the tail length in centimeters instead of millimeters, the slope of the regression line would have been 3/10=0.3

(e) One mouse weighed 29 grams and had a tail length of 100 millimeters. The residual for this mouse is −7

Short Answer

Expert verified

The correct option is (a).

Step by step solution

01

Given information

predicted tail length = 20+3×weight

02

Concept

The treatments are randomly assigned to all of the experimental units in a completely randomized design.

03

Calculation

The least significant regression line of tail length on mouse weight is

predicted taillength=20+3×weight

The slope here is 3

The rise in the length of the tail is indicated by this slope.

for an additional weight gain of grams (in millimeters).

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