What is the best way to display data which occur in pairs?

1.   ?    Time series plot
2.   ?    Histogram
3.   ?    Pie Chart
4.   ?    Scatter plot

Which of the following is not necessarily true of a correlation coefficient?

1.   ?    It takes a value between -1 and 1 inclusive
2.   ?    When it is 0, there is no relationship between the variables
3.   ?    It measures strength of linear relationship
4.   ?    When it is 1, the points lie on a line with positive gradient

Calculate the correlation coefficient for the following points: (2,5), (3,8), (5,10), (6,10), (7,12).

1.   ?    0.96
2.   ?    0.88
3.   ?    -0.94
4.   ?    0.02

Which of the following pairs of variables is most likely to have a correlation coefficient close to -1?

1.   ?    The size of a man’s shoes and his height
2.   ?    The engine size of a new car and its selling price
3.   ?    The age of a second hand car and its selling price
4.   ?    Marks scored in a test and student’s age

Fit a least squares line to the following points: (2,5), (3,8), (5,10), (6,10), (7,12).

1.   ?    y = 3.38 + 1.22x
2.   ?    y = 1.061 + 0.214x
3.   ?    y = 5.62 + 0.96x
4.   ?    y = 0.88 – 3.4x

If height (in inches) = 58.8 + 1.12 shoesize predict the height of a man with size 10 shoes.

1.   ?    6 feet
2.   ?    5 feet 10 inches
3.   ?    5 feet 11 inches
4.   ?    6 feet 2 inches

Which of the following statements is not true?

1.   ?    The coefficient of determination measures how good the least squares line is
2.   ?    The coefficient of determination is the square of the correlation coefficient
3.   ?    The coefficient of determination is a value between 0 and 1 inclusive
4.   ?    The coefficient of determination must be greater than 0.5 for there to be a useful relationship

The t-ratio calculated from a sample of 5 pairs of values to test the null hypothesis H₀: ß = 0 against H₁: ß ¹ 0 is 5.708. If the significance level is 5% what do you conclude?

1.   ?    X is not a useful predictor of Y
2.   ?    Test is not significant
3.   ?    X is a useful predictor of Y
4.   ?    Retain H₀

In multiple regression output what might you use to test the overall usefulness of the model?

1.   ?    The F test
2.   ?    The t test
3.   ?    The Model Summary
4.   ?    The Unstandardized Coefficients

10. You fit a multiple linear regression model to some data with independent variables X₁, X₂ and X₃ and obtain the following F and t test results.
F = 32.586 p = 0.001,
X₁, t = -6.508 p = 0.000; X₂, t = 3.659 p = 0.001; X₃, t = 0.338 p = 0.738. What do you conclude?

1.   ?    Model is not useful
2.   ?    When we retain X₁ and X₂ in the model, X₃ is not useful
3.   ?    When we retain X₂ and X₃ in the model, X₁ is not useful
4.   ?    When we retain X₃ in the model, X₁ and X₂ are not useful