Question

What does it mean when the slope of the best-fit line is negative?

Answer 1

That the two variables plotted are negatively correlated.

Explanation:

When plotting the slope of best-fit, there are usually 2 options available:
1. The slope will be positive (left-right)
2. The slope will be negative (right-left)
If it is negative, that means the data tends to be moving in a negative gradient. Depending on the two variables plotted for the data, the slope being negative could mean any number of things. However, that tends to be specific to that set of data, and not a rule for all data.

I hope that helped!

Answer 2

Please see below.

Explanation:

When the slope of the best-fit line is negative, look at the slope,

If it is close to zero or very very large, (i.e. `-oo`), the correlation does not exist.

But if it close to `1`, there is a good but negative correlation betwen them and it means that while one variable is increasing, other variable is decreasing.