Question

a regression was run to determine if there is a relationship between hours of tv watched per day (x) and number of situps a person can do (y).
the results of the regression were:
y=ax+b
a=-1.156
b=20.431
r²=0.595984
r=-0.772

use this to predict the number of situps a person who watches 10 hours of tv can do (to one decimal place)
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Explanation:

Step1: Identify the regression equation

The regression equation is given as \( y = ax + b \), where \( a = -1.156 \) and \( b = 20.431 \).

Step2: Substitute \( x = 10 \) into the equation

We substitute \( x = 10 \) into \( y = -1.156x + 20.431 \).
\[

$$\begin{align*} y&=-1.156\times10 + 20.431\\ &=-11.56 + 20.431\\ &= 8.871 \end{align*}$$

\]

Step3: Round to one decimal place

Rounding \( 8.871 \) to one decimal place gives \( 8.9 \).

Answer:

\( 8.9 \)