Use the given data to find the equation of the regression line. Round the final values to three significant digits, if necessary.

Managers rate employees based on job performance and attitude. The results for several selected employees are given below:

[tex]\[
\begin{array}{c|c|c|c|c|c|c|c|c|c}
\text{Performance} & 59 & 63 & 65 & 69 & 58 & 77 & 76 & 69 & 70 & 64 \\
\hline
\text{Attitude} & 72 & 67 & 78 & 82 & 75 & 87 & 92 & 83 & 87 & 78
\end{array}
\][/tex]

A. [tex]\(\hat{y} = -47.3 + 2.02 x\)[/tex]

B. [tex]\(\hat{y} = 92.3 - 0.669 x\)[/tex]

C. [tex]\(\hat{y} = 11.7 + 1.02 x\)[/tex]

D. [tex]\(\hat{y} = 2.81 + 1.35 x\)[/tex]



Answer :

To find the equation of the regression line using the given data on performance and attitude ratings, we follow these steps:

1. Calculate the Means:
- Mean of performance scores: [tex]\( \bar{x} = 67.0 \)[/tex]
- Mean of attitude scores: [tex]\( \bar{y} = 80.1 \)[/tex]

2. Calculate the Numerator and Denominator for the Slope [tex]\( b_1 \)[/tex] of the Regression Line:
- Numerator: [tex]\( \sum{(x_i - \bar{x})(y_i - \bar{y})} = 380.0 \)[/tex]
- Denominator: [tex]\( \sum{(x_i - \bar{x})^2} = 372.0 \)[/tex]

3. Calculate the Slope [tex]\( b_1 \)[/tex]:
[tex]\[ b_1 = \frac{\text{Numerator}}{\text{Denominator}} = \frac{380.0}{372.0} = 1.021505376344086 \approx 1.02 \][/tex]

4. Calculate the Intercept [tex]\( b_0 \)[/tex]:
[tex]\[ b_0 = \bar{y} - b_1 \bar{x} = 80.1 - (1.021505376344086 \times 67.0) = 11.659139784946234 \approx 11.7 \][/tex]

5. Construct the Regression Line Equation:
- Using [tex]\( b_0 \approx 11.7 \)[/tex] and [tex]\( b_1 \approx 1.02 \)[/tex], the equation of the regression line is:
[tex]\[ \hat{y} = 11.7 + 1.02x \][/tex]

Given the final options, the correct regression equation is:

[tex]\[ \boxed{\hat{y} = 11.7 + 1.02x} \][/tex]