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Chapter 3: Q T3.5. (page 201)

Scientists examined the activity level of fish at 7 different temperatures. The fish activity was rated on a scale of 0 (no activity) to 100 (maximal activity). The temperature was measured in degrees Celsius. A computer regression printout and a residual plot are given below. Notice that the horizontal axis

on the residual plot is labeled “predicted (F/T).

What was the activity level rating for the fish at a temperature of 20.4°C?

(a)86(b)83(c)80(d)66(e)3

Short Answer

Expert verified

The correct answer is (b) 83

Step by step solution

01

Given information

02

Concept

A regression line is a straight line that depicts the relationship between an explanatory variable x and a response variable y By entering any value of x into the equation of the line, you may use a regression line to anticipate the value of y for any value of x

03

Calculation

The Y-intercept is 148.617and the slope is 3.21667according to the output. The linear regression equation will be: Y⏜=148.617−3.21667X

If X=20.4°Cthen the predicted activity level will be Y⏜=148.617−3.21667X=148.617−3.21667(20.4)=82.9969≈83

As a result, option (b) is the best choice.

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