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Q. 1.2

Expert-verified

The Practice of Statistics for AP

Found in: Page 169

Book edition 4th

Author(s) David Moore,Daren Starnes,Dan Yates

Pages 809 pages

ISBN 9781319113339

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Short Answer

Some data were collected on the weight of a male white laboratory rat for the first 25 weeks after its birth. A scatterplot of the weight (in grams) and time since birth (in weeks) shows a fairly strong, positive linear relationship. The linear regression equation weight = 100 + 40(time) models the data fairly well.
2. What’s the y intercept? Explain what it means in context.

The value of y-intercept $(a)$ is $100$

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Step by Step Solution

TABLE OF CONTENTS :

TABLE OF CONTENTS

Given

We are given the linear regression equation of weight on time:

$weight = 100 + 40(time)$

Calculation

We know that for a linear regression equation of the form:

$y = a + b x$

The value of y-intercept is a.

Therefore value of y-intercept for the given equation will be $100 .$

Interpretation

The value of y-intercept that is $a = 100$ means that if we were to keep the value of time 0, weight will be 100. That is initally we assume the weight to be $100 units.$

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