Correlation
In a ____________ correlation, those who score high on one variable tend to score low on the other.
Negative
The extent or degree to which two variables are related.
Correlation
What is the formula for calculating a residual?
Data value minus predicted value.
y - [y hat]
What is the formula used in Desmos to create a regression line?
y1~mx1+b
If correlation coefficient is negative, what can you determine about the slope of the regression line?
That it is negative?
What are the two 'things' that correlation measures?
Strength & direction
What is the variable 'r' called?
Correlation coefficient
What variable is used to represent residuals?
e
In a scatterplot that predicts income from number of years in school, which variable is the response variable?
Income
What do we call a graphical depiction of correlation?
Scatterplot.
Describe the correlation: as scores on one variable decrease, scores on the second variable decrease.
Positive correlation
The variable that is being predicted from.
Explanatory
When a residual is positive, it means that a known data value is _____________ than its predicted variable.
larger, or bigger.
What do you use the regression line to do?
Make predictions.
Even though two variables may be strongly correlated, you should not assume that:
That one variable causes the other.
What is the strongest correlation possible?
both positive and negative one
What do we call the variable that unintentionally affects the correlation between two different variables?
Lurking variable
When does a residual equal zero?
When the data point is equal to the prediction.
Interpret the y-intercept of the given regression equation that predicts the milligrams of potassium from the grams of fiber in breakfast cereals.
When a breakfast cereal has zero grams of fiber, it should have 37 milligrams of potassium.
Estimate the r-value of the given scatterplot.
0.76
If a scatterplot's r = -.9, what is the kind of relationship shown? Use at least two words to accurately describe.
What is strong negative linear relationship?
What are two different names for a regression line?
Trend line, Line of best fit, or Least squares line.
If y-hat = 5 + 3 x and an observed data point is (2,7), what is the residual for that point?
-4?
[x is the amount of textbook pages read and y is the score on the final exam, use the regression line given.] If you have read 100 pages of your textbook, what would you predict that your final exam score would be?
85
If a data set includes the point (1.5, 3.26) and the residual for this coordinate is -1.2, what is the predicted value for the given point?
y-hat = -4.46