Scatter Plots - Correlations

SCATTER PLOTS:

CORRELATIONS

* Positive vs Negative

* Strong vs Weak

TYPES OF CORRELATIONS

STRONG

* Points are close together

* Very close to forming an invisible line.

WEAK

* Points are spread out

* Points "sort of" form a line

* If you can observe any pattern or common direction, it's weak.

EXAMPLES

STRONG because the data is very closely linked

* Study Time & Test Average (positive)

* Hours Worked & Money Earned (positive)

* Gallons of Pesticides Used & Number of Insects (negative)

WEAK because there is a faint link between the two

* Car Weight & Fuel Economy [miles per gallon] (negative)

* Videos Posted & Followers (positive)

* Number of Kids & Total Savings (negative)

TYPES OF CORRELATIONS

POSITIVE

* Points are headed upwards / increasing

* Focus on the y-coordinates / axis.

NEGATIVE

* Points are headed downward / decreasing

* Focus on the y-coordinates / axis.

NO CORRELATION

* Points are random and scattered

* No visible pattern at all

EXAMPLES

POSITIVE because the 2nd data set is increasing

* Items Sold & Profit (strong)

* Years of Experience & Salary (weak)

* Hours of Exercise & Hours of Sleep (weak)

NEGATIVE because the 2nd data set is decreasing

* Hours Watching TV & Hours Reading (weak)

* Pollution Levels & Fish Population (strong)

* Length Of Pregnancy & Pounds Under Weight (strong)

EXAMPLES - NO CORRELATION

NO CORRELATION because the 2nd data set is not linked to the 1st

* Age & Hours Spent Sleeping

* Weight & Salary

* Vaccines Administered & Cases Of Autism