College

Run a regression analysis on the following data set, where [tex] y [/tex] is the final grade in a math class and [tex] x [/tex] is the average number of hours the student spent working on math each week.

[tex]
\begin{array}{|c|c|}
\hline
\text{Hours/Week} \, (x) & \text{Grade} \, (y) \\
\hline
5 & 46 \\
\hline
9 & 64.6 \\
\hline
11 & 79.4 \\
\hline
13 & 77.2 \\
\hline
14 & 78.6 \\
\hline
14 & 85.6 \\
\hline
14 & 77.6 \\
\hline
15 & 97 \\
\hline
17 & 97.8 \\
\hline
19 & 100 \\
\hline
\end{array}
[/tex]

State the regression equation [tex] y = m \cdot x + b [/tex], with constants accurate to two decimal places.

What is the predicted value for the final grade when a student spends an average of 13 hours each week on math?

Grade = [tex] \square [/tex] Round to 1 decimal place.

Answer :

To find the regression equation for the provided data set, where [tex]$y$[/tex] is the final grade in a math class and [tex]$x$[/tex] is the average number of hours spent on math each week, follow these steps:

### Step 1: Calculate the Regression Equation

The regression equation is of the form:
[tex]\[ y = m \cdot x + b \][/tex]

Where:
- [tex]\( m \)[/tex] is the slope of the line.
- [tex]\( b \)[/tex] is the y-intercept of the line.

For the given data:
- Hours per week ([tex]$x$[/tex]): [5, 9, 11, 13, 14, 14, 14, 15, 17, 19]
- Grades ([tex]$y$[/tex]): [46, 64.6, 79.4, 77.2, 78.6, 85.6, 77.6, 97, 97.8, 100]

From the analysis, it was found that:

- The slope [tex]\( m \approx 3.93 \)[/tex]
- The intercept [tex]\( b \approx 28.91 \)[/tex]

So, the regression equation is:

[tex]\[ y = 3.93 \cdot x + 28.91 \][/tex]

### Step 2: Predict the Final Grade

Now, we want to predict the final grade for a student who spends an average of 13 hours per week on math. Using the regression equation:

Substitute [tex]\( x = 13 \)[/tex] into the equation:

[tex]\[ y = 3.93 \cdot 13 + 28.91 \][/tex]

Calculate the value:

[tex]\[ y = 51.09 + 28.91 \][/tex]

[tex]\[ y \approx 80.0 \][/tex]

Therefore, the predicted final grade when a student spends an average of 13 hours each week on math is approximately 80.0 when rounded to 1 decimal place.

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