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

Two different tests are designed to measure employee productivity and dexterity. Several employees are randomly selected and tested with these results.

[tex]\[
\begin{array}{c|c|c|c|c|c|c|c|c|c}
\text{Productivity} & 23 & 25 & 28 & 21 & 21 & 25 & 26 & 30 & 34 & 36 \\
\hline
\text{Dexterity} & 49 & 53 & 59 & 42 & 47 & 53 & 55 & 63 & 67 & 75
\end{array}
\][/tex]

(1 point)

A. [tex]$\hat{y} = 5.05 + 1.91 x$[/tex]

B. [tex]$\hat{y} = 2.36 + 2.03 x$[/tex]

C. [tex]$\hat{y} = 10.7 + 1.53 x$[/tex]

D. [tex]$\hat{y} = 75.3 - 0.329 x$[/tex]



Answer :

To find the equation of the regression line for the given data, we should follow these steps:

1. Calculate the Mean of Productivity and Dexterity:

[tex]\[ \text{Mean Productivity} (\bar{x}) = \frac{23 + 25 + 28 + 21 + 21 + 25 + 26 + 30 + 34 + 36}{10} = 26.9 \][/tex]

[tex]\[ \text{Mean Dexterity} (\bar{y}) = \frac{49 + 53 + 59 + 42 + 47 + 53 + 55 + 63 + 67 + 75}{10} = 56.3 \][/tex]

2. Calculate the Slope (b1) for the Regression Line:

The slope [tex]\( b_1 \)[/tex] is given by:
[tex]\[ b_1 = \frac{\sum (x_i - \bar{x})(y_i - \bar{y})}{\sum (x_i - \bar{x})^2} \][/tex]

Given the values, this calculation has been determined as:
[tex]\[ b_1 = 1.905 \][/tex]

3. Calculate the Intercept (b0) for the Regression Line:

The intercept [tex]\( b_0 \)[/tex] is given by:
[tex]\[ b_0 = \bar{y} - b_1 \cdot \bar{x} \][/tex]

Using the values:
[tex]\[ b_0 = 56.3 - (1.905 \cdot 26.9) = 5.055 \][/tex]

4. Formulate the Regression Line Equation:

The equation of the regression line is:
[tex]\[ \hat{y} = b_0 + b_1 x \][/tex]

Plugging in the calculated values:
[tex]\[ \hat{y} = 5.055 + 1.905 x \][/tex]

Rounding to three significant digits where necessary, we have:

[tex]\( \boxed{\hat{y} = 5.05 + 1.91x} \)[/tex]

Thus, the correct regression equation is:

[tex]\( \boxed{\hat{y} = 5.05 + 1.91x} \)[/tex]