FINAL EXAM IN STAT 11A

The equation of the regression line used in statistics is _________________.         

• x = ay + b

• ŷ = a + bx       

The coefficient of determination is ________________.

• r

• r²

Four pairs of data yield r = 0.942 and the regression equation ŷ = 3x. Also, Ῡ= 12.75. What is the best predicted value of Y for X = 2.5?

• 0.942

• 7.5      

The regression equation relating attitude rating (X) and job performance rating (Y) for the employees of a company is ŷ = 11.7 + 1.02x. Ten pairs of data were used to obtain the equation. The same data yield r = 0.863 and Ῡ = 80.1. What is the best predicted job performance rating for a person whose attitude rating is 70?

• 83.1    

• 81.9

Use the given data to find the equation of the regression line.

            X            2            4            5            6              

Y            7           11          13           20      

• ŷ = 3.0x      

• ŷ = 0.15 + 3.0x

The heights Y of 40 men and their shoes sizes X were obtained. The variable height is measured in centimeters (cm) and the shoe sizes of these 40 men ranged from 8 to 11. From these 40 pairs of observations, the equation of the regression line predicting height from shoe size was computed to be ŷ = 130.455 + 4.7498x. What is the likely height of a man with a shoe size of 13?

• 182.70cm

• 192.20cm

Which of the following indicators the strongest relationship?

• r = -0.6

• r² = 0.2

The coefficient of determination

• is maximized by ordinary least squares.

• has a value between zero and one.

• will generally increase if additional independent variables are added to a regression analysis.

• All of the above are correct.

In the simple linear regression equation, the term b_o represents the

• estimated or predicted response

• estimated intercept

A regression between foot length (response variable in cm) and height (explanatory variable in inches) for 33 students resulted in the following regression equation: yˆ = 10.9 + 0.23x. One student in the sample was 73 inches tall with a foot length of 29 cm. What is the predicted foot length for this student? 

• 17.57 cm

• 27.69 cm