Least Squares Regression Line Practice

Least Squares Regression Line Practice

Coney Hon Stats

Fill in the Blank

Y-hat is the ________ value of y for a given value of x.

Multiple Choice

What is the formula for the regression line?

• y=mx+b

• 
  

  $y^{\wedge}=ax+b$

• y=a+bx

• $y^{\wedge}=a+bx$

Multiple Choice

To make a prediction using the regression line, you would...

• plug in a predicted guess for y-hat and simplify

• look at the scatterplot

• rearrange the equation to solve for x

• plug in a value for x and simplify

Fill in the Blank

_____________________ is the use of a regression line for prediction outside the interval of x values used to obtain the line.

Multiple Select

A residual...

• the difference between the actual value of y and the value of y predicted by the regression line

• actual y - predicted y

• $y-y^{\wedge}$

• the difference between the actual value of x and the value of x predicted by the regression line

Multiple Choice

What should a residual plot look like?

• Distinct Pattern

• Curve

• Random with no pattern

• A few clumps

Multiple Choice

Shown is a residual plot. Would a linear regression model of the data be most appropriate?

• YES

• NO

Multiple Choice

Estimate the correlation coefficient.

• r = -0.8

• r = -0.5

• r = 0.5

• r = 0.8

Multiple Choice

Shown is a residual plot. Would a linear regression model of the data be most appropriate?

• YES
• NO

Multiple Choice

A correlation shows that two things are

• related
• causing each other
• unrelated
• causation

Multiple Choice

What type of correlation?

• Positive Correlation

• Negative Correlation

• No Correlation

Multiple Choice

Number of days absent from school vs. math average

• Positive Correlation

• Negative Correlation

• No Correlation

Multiple Choice

What type of association does this graph show?

• Positive
• negative
• none
• all of the above

Multiple Choice

What type of association does this graph have?

• positive 
• negative
• none
• all of the above

Multiple Choice

What type of correlation describes the following sentence:
The temperature outside and the number of hot chocolate sold at a football game.

• postive
• negative 
• no

Multiple Choice

You are analyzing a scatter plot that has a negative correlation. What is true of the of the x and y values?

• As x increases, y decreases
• As x increases, y increases
• As x decreases, y decreases