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a.
To explain: The slope of the provided equation line in words and the reason of considering zero.
a.
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Explanation of Solution
Given:
The equation of the regression line is:
he general equation of the least squares line is:
Here, a represents the y-intercept and b represents the slope of the line.
By comparing the general equation of the least-squares line with the provided equation of a least squares line, it can be said that the slope of the
A positive slope indicates that an average increase (or decrease) in the value of y for each unit increase (or decrease) in the value of x . A negative slope indicates that an average increase (or decrease) in the value of y for each unit decrease (or increase) in the value of x .
The provided least squares line has a slope of 0.023. So, the value of BAC increases by 0.023 for a unit increase in number of drinks.
Here, the provided least square line does not contain the intercept term. Thus, it could be said that the intercept term is
b.
To find: The equation of the regression line that could be used to predict BAC from number of drinks for a 120-pound woman.
b.
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Explanation of Solution
Using the provided information, the equation of the regression line that could be used to predict BAC from number of drinks for a 120-pound woman could be written as:
c.
To find: The predicted BAC for a 160-pound male who consumed 4 drinks and for 120-pound women that consumed 2 drinks.
c.
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Explanation of Solution
The predicted BAC for a 160-pound male who consumed 4 drinks can be calculated as:
Now, the predicted BAC for 120-pound women who consumed 2 drinks can be calculated as:
The obtained values of BAC for male and female do not depict the actual blood alcohol content because there would be other factors that would affect the alcohol content in the body
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Chapter 4 Solutions
Practice of Statistics in the Life Sciences
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