Question

A mathematics teacher wanted to see the correlation between test scores and

Answer 1

Answer:

The homework  grade, to the nearest integer, for a student with a test grade of 68 is 69.

Step-by-step explanation:

The general form of the linear regression equation is:

$y=a+bx$

Here,

y = dependent variable = test grade

x = independent variable = homework grade

a = intercept

b = slope

Compute the value of a and b as follows:

$a=\frac{\sum Y\cdot \sum X^{2}-\sum X\cdot\sum XY}{n\cdot \sum X^{2}-(\sum X)^{2}}\\\\=\frac{(592\times 44909)-(591\times45227)}{(8\times44909)-(591)^{2}}\\\\=-14.316$                $b=\frac{n\cdot \sum XY-\sum X\cdot\sum Y}{n\cdot \sum X^{2}-(\sum X)^{2}}\\\\=\frac{(8\times 45227)-(591\592)}{(8\times44909)-(591)^{2}}\\\\=1.195$

The linear regression equation that represents the set of data is:

$y=-14.316+1.195x$

Compute the value of x for y = 68 as follows:

$y=-14.316+1.195x$

$68=-14.316+1.195x\\1.195x=68+14.316\\1.195x=82.316\\x=68.884\\x\approx 69$

Thus, the homework  grade, to the nearest integer, for a student with a test grade of 68 is 69.