Identifying Parts of Equations: b

Error

There was an error loading the page.

Contributors

Feedback

From users who are not members of Hayley's workspace :

Christian Lawson-Perfect

said

Ready to use

9 years, 5 months ago

History

○

Christian Lawson-Perfect 9 years, 5 months ago

Saved a checkpoint:

Give a mark for part c

Restore this checkpoint

○

Christian Lawson-Perfect 9 years, 5 months ago

Gave some feedback: Ready to use

○

Christian Lawson-Perfect 9 years, 5 months ago

Saved a checkpoint:

Some formatting changes.
Changed part c, because I'm not sure what it was asking for is possible. It said, "if $x_i-\bar{x}$ increases for every i, what happens to b?"
$x_i - \bar{x}$ can't increase for every i, because the mean would move.
You could say $\lvert x_i - \bar{x} \rvert$ increases, but that's getting a bit complicated. You would never think about things this way, anyway.

Restore this checkpoint

○

Hayley Moore 9 years, 7 months ago

Created this.

There is only one version of this question that you have access to.

Question statement

Given that

$b = \dfrac{\sum(x_i-\bar{x})(y_i-\bar{y})}{\sum(x_i-\bar{x})^2},$

answer the following questions.

Give any introductory information the student needs.

			Name	Type	Generated Value

change	list	[ "increases", "decreases" ]
changes	string	decreases
r	integer	1
change2	list	[ "decreases", "increases" ]
correct	string	increases

Automatically regenerate variables?

Name

Data type

Value

(text strings)

Description

Describe what this variable represents, and list any assumptions made about its value.

Can an exam override the value of this variable?

Generated value: `list`

[ "increases", "decreases" ]

→ Used by:

change2
changes

Choose several from a list

Ask the student a question, and give any hints about how they should answer this part.

Which of the following is equivalent to the given equation for $b$ ?

Minimum marks

Maximum marks

(no maximum)

Show correct answer on reveal?

Show score feedback icon?

Advanced settings

Number of display columns

Minimum answers

Maximum answers

(no maximum)

What to do if wrong number of answers selected:

Custom marking matrix?

Show choice feedback state?

Marking method

For each choice, specify the number of marks to add or subtract when the student picks it.

Variable list of choices?

Shuffle order of choices?

$b = \frac{ \sum(xy)-\frac{\sum{x} \sum{y}}{n}}{\sum(x^2)-\frac{(\sum{x})^2}{n}}\\$

Marks: Distractor Message:
$b = \frac{n \sum(xy)-\sum{x} \sum{y}}{n\sum(x^2)-(\sum{x})^2}\\$

Marks: Distractor Message:
$b = \dfrac{\sum(y_i-\bar{y})}{\sum(x_i-\bar{x})}\\$

Marks: Distractor Message:
$b = \dfrac{\sum(x_iy_i-\overline{xy})}{\sum(x_i-\bar{x})^2}\\$

Marks: Distractor Message:
$b = \dfrac{\sum(x_iy_i-\bar{x}\bar{y})}{\sum(x_i-\bar{x})^2}\\$

Marks: Distractor Message:

Advice

Give a worked solution to the whole question.

Use this tab to check that this question works as expected.

There was an error which means the tests can't run:

Part	Test	Passed?
Choose several from a list
Choose several from a list		Hasn't run yet
Choose one from a list
Choose one from a list		Hasn't run yet
Number entry
Number entry		Hasn't run yet

This question is used in the following exam:

Identifying parts of statistical formulas by Christian Lawson-Perfect in Christian's workspace.

Loading...

Error

Metadata

Taxonomy: mathcentre

Taxonomy: Kind of activity

Taxonomy: Context

Contributors

Feedback

History

Comment

Checkpoint description

Christian Lawson-Perfect 9 years, 5 months ago

Christian Lawson-Perfect 9 years, 5 months ago

Christian Lawson-Perfect 9 years, 5 months ago

Hayley Moore 9 years, 7 months ago

Error in variable testing condition

Error

Warning

Generated value: `list`

Parts

Choose several from a list

Advanced settings

Loading...

Error

Identifying Parts of Equations: b

Metadata

Taxonomy: mathcentre

Taxonomy: Kind of activity

Taxonomy: Context

Contributors

Feedback

History

Comment

Checkpoint description

Christian Lawson-Perfect 9 years, 5 months ago

Christian Lawson-Perfect 9 years, 5 months ago

Christian Lawson-Perfect 9 years, 5 months ago

Hayley Moore 9 years, 7 months ago

Error in variable testing condition

Error

Warning

Generated value: list

Parts

Choose several from a list

Advanced settings

Generated value: `list`