Testing an hypothesis about the mean of a group (1).

Error

There was an error loading the page.

Contributors

Keith McGuinness

Feedback

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

Christian Lawson-Perfect

said

Ready to use

8 years, 9 months ago

History

○

Christian Lawson-Perfect 8 years, 9 months ago

Gave some feedback: Ready to use

○

Keith McGuinness 9 years, 8 months ago

Created this as a copy of A comparison of the means of two groups (1)..

Name	Status	Author	Last Modified
Paired t-test after treatment.	Ready to use	Bill Foster	01/06/2016 09:47
Christian's copy of Paired t-test after treatment.	Ready to use	Christian Lawson-Perfect	01/06/2016 10:06
A comparison of the means of two groups (1).	Ready to use	Keith McGuinness	01/06/2016 09:47
A comparison of the means of two groups (2).	Ready to use	Keith McGuinness	01/06/2016 09:47
Testing an hypothesis about the mean of a group (1).	Ready to use	Keith McGuinness	01/06/2016 09:47
Testing an hypothesis about the mean of a group (2).	Ready to use	Keith McGuinness	01/06/2016 09:47
Summary statistics (1).	Ready to use	Keith McGuinness	01/06/2016 09:47
A comparison of the means of two groups (3).	Ready to use	Keith McGuinness	01/06/2016 09:47
A comparison of the means of two groups (4).	Ready to use	Keith McGuinness	01/06/2016 09:47
A comparison of the means of three groups (1).	Ready to use	Keith McGuinness	01/06/2016 09:47
A comparison of the means of three groups (2).	Ready to use	Keith McGuinness	01/06/2016 09:47
A comparison of the means of four groups (1).	Ready to use	Keith McGuinness	01/06/2016 09:47
Simon's copy of Paired t-test after treatment.	draft	Simon Thomas	05/06/2019 14:44

There are 2 other versions that do you not have access to.

Question statement

The Arnott’s biscuit company makes "snack packs" of many of its products, including Tiny Teddy (TT) and Pizza Shapes (PS). These packs are labelled "25 g". Test if TT meet the stated weight content. Sample data are in the table below:

{object}	A	B	C	D	E	F
Weight (g)	$\var{r1[0]}$	$\var{r1[1]}$	$\var{r1[2]}$	$\var{r1[3]}$	$\var{r1[4]}$	$\var{r1[5]}$

Are the packets, on average, the correct weight?

In other words, test the following null hypothesis:

H0: Mean weight is equal to 25 g.

Give any introductory information the student needs.

			Name	Type	Generated Value

mu1	number	27.5
r1	list	[ 25, 25, 25, 23, 24, 25 ]
sig1	number	2.2
t95	number	2.571
thismany	integer	6
tcalc	number	-1.463
tupper	number	-1.438
tlower	number	-1.488
mdupper	number	24.525
mdlower	number	24.475
stdupper	number	0.862
stdlower	number	0.812
outcome	integer	0
sed	number	0.342
meanwgt	number	24.500
sdwgt	number	0.837
hypval	integer	25

Automatically regenerate variables?

Name

Data type

Value

xxxxxxxxxx
 
random(22..28#0.5)

JME function reference

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: `number`

27.5

This variable doesn't seem to be used anywhere.

Parts

Gap-fill
1. Gap Gap 0. Number entry
  Add
2. Gap Gap 1. Number entry
  Add
3. Gap Gap 2. Number entry
  Add
4. Gap Gap 3. Number entry
  Add

Gap-fill

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

Find the mean and standard deviation of the sample.

Mean = Gap 0. (input to 2 decimal places )

Standard deviation = Gap 1. (input to 2 decimal places)

Now find the one sample (or "mean to hypothetical value") t-test statistic using the values you have just calculated =Gap 2. (input 2 decimal places)

Is the null hypothesis rejected? Gap 3. Enter 0 for "No" and 1 for "Yes".

Advice

First, recognise that this is a one-sample (or "mean to hypothetical value") t-test.

So calculate the mean of the sample:

{meanwgt}

Then the standard deviation (sd) of the sample:

{sdwgt}

Note: You should use your calculator to get both the mean and standard deviation.

The standard error (se) is calculated as:

\[ se = \frac{ sd }{ \sqrt{ n }} \]

It is:

{sed}

Finally, calculate the test statisitic, t-calc, as the mean difference divided by the standard error:

\[ t-calc = \frac{ mean difference }{ se} \]

t-calc = {tcalc}

There are 6 {objects}, so 5 degrees of freedom, and the test is two-tailed, so the t-table = 2.571.

If t-calc is greater than 2.571, the null is rejected. As this is a two-tailed test, the sign of t-calc (positive or negative) is ignored.

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?
Gap-fill
Gap-fill		Hasn't run yet
Number entry
Number entry		Hasn't run yet
Number entry
Number entry		Hasn't run yet
Number entry
Number entry		Hasn't run yet
Number entry
Number entry		Hasn't run yet

This question is not used in any exams.

Loading...

Error

Testing an hypothesis about the mean of a group (1).

Metadata

Taxonomy: mathcentre

Taxonomy: Kind of activity

Taxonomy: Context

Contributors

Feedback

History

Comment

Checkpoint description

Christian Lawson-Perfect 8 years, 9 months ago

Keith McGuinness 9 years, 8 months ago

Error in variable testing condition

Error

Warning

Generated value: `number`

Parts

Gap-fill

Loading...

Error

Testing an hypothesis about the mean of a group (1).

Metadata

Taxonomy: mathcentre

Taxonomy: Kind of activity

Taxonomy: Context

Contributors

Feedback

History

Comment

Checkpoint description

Christian Lawson-Perfect 8 years, 9 months ago

Keith McGuinness 9 years, 8 months ago

Error in variable testing condition

Error

Warning

Generated value: number

Parts

Gap-fill

Generated value: `number`