Simple Linear Regression Flashcards

1
Q

A numerical measure of linear association between two variables is the

A

covariance

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2
Q

A numerical measure of linear association between two variables is the

A

correlation coefficient

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3
Q

The coefficient of correlation

A

cannot be larger than 1

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4
Q

In a regression analysis, the error term  is a random variable with a mean or expected value of

A

zero

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5
Q

The mathematical equation relating the independent variable to the expected value of the dependent variable; that is, E(y) = 0 + 1x, is known as

A

regression equation

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6
Q

A regression analysis between sales (Y in $1000) and advertising (X in dollars) resulted in the following equation
Y hat= 30,000 + 4 X

A

increase of $1 in advertising is associated with an increase of $4,000 in sales

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7
Q

In a simple regression analysis (where Y is a dependent and X an independent variable), if the Y intercept is positive, then

A

None of these alternatives is correct.

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8
Q

The equation that describes how the dependent variable (y) is related to the independent variable (x) is called

A

the regression model

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9
Q

In a regression analysis, the variable that is being predicted

A

is the dependent variable

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10
Q

A regression analysis between sales (in $1000) and price (in dollars) resulted in the following equation
Y hat = 60 - 8X
The above equation implies that an

A

increase of $1 in price is associated with a decrease of $8000 in sales

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11
Q

A regression analysis between demand (Y in 1000 units) and price (X in dollars) resulted in the following equation
Y8 = 9 - 3X
The above equation implies that if the price is increased by $1, the demand is expected to

A

decrease by 3,000 units

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12
Q

A least squares regression line

A

may be used to predict a value of y if the corresponding x value is given

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13
Q

The coefficient of determination

A

cannot be negative

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14
Q

The value of the coefficient of correlation (R)

A

can be equal to the value of the coefficient of determination (R2)

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15
Q

In a regression analysis, the coefficient of determination is 0.4225. The coefficient of correlation in this situation is

A

0.65

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16
Q

Correlation analysis is used to determine

A

the strength of the relationship between the dependent and the independent variables

17
Q

In a regression and correlation analysis if r squared = 1, then

A

SSR = SST

18
Q

In a regression analysis if SSE = 200 and SSR = 300, then the coefficient of determination is

A

0.6000

19
Q

If the coefficient of correlation is a positive value, then the regression equation

A

must have a positive slope

20
Q

In regression and correlation analysis, if SSE and SST are known, then with this information the

A

coefficient of determination can be computed

21
Q

SSE can never be

A

larger than SST

22
Q

If the coefficient of correlation is a negative value, then the coefficient of determination

A

must be positive

23
Q

If two variables, x and y, have a strong linear relationship, then

A

there may or may not be any causal relationship between x and y

24
Q

If all the points of a scatter diagram lie on the least squares regression line, then the coefficient of determination for these variables based on these data is

A

1

25
Q

In a regression analysis if SST = 500 and SSE = 300, then the coefficient of determination is

A

0.40

26
Q

If the coefficient of correlation is 0.4, the percentage of variation in the dependent variable explained by the variation in the independent variable

A

is 16%.

27
Q

If the coefficient of correlation is 0.90, then the coefficient of determination

A

must be 0.81

28
Q

If the coefficient of correlation is a positive value, then

A

the slope of the line must be positive

29
Q

In regression analysis, which of the following is not a required assumption about the error term (backward 3)

A

The expected value of the error term is one.

30
Q

In regression analysis, the unbiased estimate of the variance is

A

mean square error

31
Q

If only MSE is known, you can compute the

A

standard error

32
Q

In simple linear regression analysis, which of the following is not true?

A

The F test and the t test may or may not yield the same conclusion.

33
Q

The interval estimate of the mean value of y for a given value of x is

A

confidence interval estimate

34
Q

Regression analysis was applied between demand for a product (Y) and the price of the product (X), and the following estimated regression equation was obtained.
Y hat = 120 - 10 X
Based on the above estimated regression equation, if price is increased by 2 units, then demand is expected to

A

decease by 20 units

35
Q

Regression analysis was applied between sales (in $1000) and advertising (in $100) and the following regression function was obtained.
Y hat = 500 + 4 X
Based on the above estimated regression line if advertising is $10,000, then the point estimate for sales (in dollars) is

A

$900,000

36
Q

Regression analysis was applied between sales (Y in $1,000) and advertising (X in $100), and the following estimated regression equation was obtained.
Y hat = 80 + 6.2 X
Based on the above estimated regression line, if advertising is $10,000, then the point estimate for sales (in dollars) is

A

$700,000