Correlations (Situation)
Hours of exercise and weight loss.
Positive
What is an outlier?
A point that is distant (skewed) from the rest of the data.
Two points on the line of best fit are (4, 85) and (2, 70). Find the slope for the line of best fit using these points.
15/2
Why do we draw a line of best fit?
To predict a trend.
Temperature outside and amount of snow-cones sold
Positive
Describe what a positive correlation means for data.
As the independent variable increases the dependent variable will also increase.
The equation of the line for a graph comparing age and height (ft) is y=0.25x+1. How tall would someone that is 20 years old be?
6 feet tall
Which axis on a graph has the independent variable?
x axis
Temperature outside and number of pets
No correlation
What does it mean for the data if there is no correlation?
The sets of data have no relationship to each other. You cannot draw a best-fit line.
Which axis on a graph has the dependent variable?
y axis
Do you use a line of best fit for no correlation? How / why?
No, if there is no correlation, it is not possible to predict the trend, therefore, it is not possible to have a best-fit line.
Time spent doing homework and number of missing assignments.
Negative
When the values of one data set increase and the others decrease, this is called a ___________ correlation.
Negative
Line of best fit should connect all the dots (T/F). Justify
False. The best-fit line will most likely not go through all the points.
On a graph showing the relationship between salary and years of experience which variable would be the dependent variable?
The salary.
Number of visitors to a water park and temperature.
Positive
How do you determine where to place the line of best fit?
There should be close to as many points as possible, and it should have an equal number of points above and below the line.
If there is no correlation-is the slope of the line positive or negative?
There's no line!
If I am graphing the number of shots made by a basketball player and the hours of practice he had, which would be the independent variable?
The number of hours played.