Bivariate Statistics Flashcards

1
Q

Why do you have to take note of the saved function f when doing a linear regression?

A

So you can use the saved function later to predict outputs.

You click the var button in a calculator tab and choose the correct function.

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2
Q

What would a scatter plot look like if r = 1 ?

A
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3
Q

What would a scatter plot look like if r = 0.9 ?

A
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4
Q

What does this symbol represent?

A

Pronounced “x bar”, this symbol represents the mean for the variable x.

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5
Q

What is the fancy calculator name for “line of best fit “ ?

A

Linear Regression (mx+b)

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6
Q

What does it mean if r = 0 ?

A

There is no correlation between the two variables.

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7
Q

What are the lowest and greatest values r can be?

A

The lowest r can be is -1.

The greatest r can be is +1.

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8
Q

What would a scatter plot look like if r = 0 ?

A
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9
Q

What does b stand for in the equation for a straight line?

y = mx + b

A

b is the y-intercept

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10
Q

What does it mean if r = 1 ?

A

The two variables are perfectly positively correlated.

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11
Q

What would a scatter plot look like if r = -0.5 ?

A
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12
Q

What is the equation for the regression line (aka any straight line)?

A
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13
Q

What would a scatter plot look like if r = 0.5 ?

A
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14
Q

What are the many names we use for correlation?

A

All of these names refer to the same thing.

  • Pearson correlation coefficient
  • Pearson product-moment correlation coefficient
  • Pearson’s r
  • bivariate correlation
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15
Q

What would a scatter plot look like if r = -1 ?

A
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16
Q

For which x-values are you allowed to use your linear regression predictions?

A

Only for those that are inside the domain of the original data.

This means, if the scatter plot only has data from x between 2 and 10, you can only use predictions for x-values between 2 and 10.

17
Q

What does this symbol represent?

A

Pronounced “y bar”, this symbol represents the mean for the variable y.

18
Q

What letter do we use for correlation?

A

r

19
Q

What does m stand for in the linear regression line?

y = mx + b

A

m is the gradient

20
Q

What would a scatter plot look like if r = -0.9 ?

A
21
Q

What does it mean if r = -1 ?

A

The two variables are perfectly negatively correlated.

22
Q

Where do I find b, the y-intercept of the linear regression line in the calculator output?

A
23
Q

Where do I find m, the gradient of the linear regression line, in the calculator output?

A