Question

A scatter plot displays 12 individual data points, each marked by a black circle, plotted against a grid.
Write an equation in slope-intercept form of the trend line.

Answer 1

I don't have the scatter-plot image or the coordinates, so I can't write the exact trend-line equation yet. Please either upload the plot image or list the 12 (x,y) data points.

How you (or I) can find the trend line once I have the plot/points:

1. Quick/graphical method (if the points visually lie near a line):
- Pick two points that appear to lie on the trend line (or pick two points that are symmetric about the cloud).
- Compute slope m = (y2 − y1)/(x2 − x1).
- Compute intercept b by plugging one point into y = mx + b so b = y1 − m x1.
- The trend line is y = m x + b.

2. Exact least-squares method (best fit for the given data):
- Using the data points (xi, yi) for i = 1..n:
m = [nΣ(xi yi) − Σxi Σyi] / [nΣ(xi^2) − (Σxi)^2]
b = (Σyi − m Σxi) / n
- (Equivalent formula using means: m = Σ(xi−x̄)(yi−ȳ) / Σ(xi−x̄)^2 and b = ȳ − m x̄.)
- You can compute these by hand, with a calculator, or use Excel/Google Sheets (LINEST or SLOPE/INTERCEPT) or a graphing calculator.

If you upload the image or paste the 12 coordinates, I’ll compute the slope-intercept equation for you.