Unit seven scatterplot and data analysis lesson six trend lines. Write an equation in slope intercept form of the trend line.

Answer 1

To write an equation in slope-intercept form of a trend line, first calculate the slope of the trend line. The formula for the slope of a trend line is:

$$m=\frac{n(\sum xy)-(\sum x)(\sum y)}{n(\sum x^2)-(\sum x{)}^2}$$

Where:
m = slope of the trend line
n = number of data points
$\sum xy$ = sum of the products of x and y values
$\sum x$ = sum of x values
$\sum y$ = sum of y values
$\sum x^2$ = sum of the squared values of x

Once you have calculated the slope, you can then calculate the y-intercept using the formula:

$$b=\frac{\sum y-m(\sum x)}{n}$$

Where:
b = y-intercept

Finally, you can write the equation of the trend line in slope-intercept form as:

$$y=mx+b$$

Plug in the values of m and b that you calculated to get the final equation in slope-intercept form of the trend line.