BUSINESS STRATEGIES

Business Strategies



Business Strategies

ASSIGNMENT COVERSHEET FOR BUS105 Stats assignment due 8th of october

Worth 10% of your final grade

Do the assignment with in a group of 4 students

Assignment receipt - only one student needs to get a receipt

Student's surname and first name:

Unit title: BUS105

Lecturer: Matthew Maccallum

Assignment number: 3

Assignment title: 10% assignment due on 8th of October

Date: Signature1)Fill in the blanks if there is no evidence against the claim the variables are independent

(assume you are doing market research to see if people like the ending of a movie)

Like ending

Hate ending

Total

Sample 1

20

100

Sample 2

200

Total

(1 mark) 2) Fill in the blanks if there is no evidence against independence

(assume you are doing market research to see if people like the ending of a movie)

Like ending

Hate ending

Total

Sample 1

30

120

Sample 2

Total

90

(1 mark)

3)consider the following two way table that summarizes of size n=200

(assume you are doing market research to see if people like the ending of a movie)

Like ending

Hate ending

Total

Males

65

35

100

Females

35

65

100

Total

100

100

200

Test the claim of independence use a 1% level of significance

(3 marks)

4)Test the claim of independence using the two way table below.

 

Old

 Young

Total

PS2

7

43

50

Wii

60

440

500

Xbox360

58

392

450

Total

125

875

1000

Hint expected values if the null hypothesis of independence is true are

 

Old

 Young

Total

PS2

6.25

43.75

50

Wii

62.5

437.5

500

Xbox360

56.25

393.75

450

Total

125

875

1000

(4 marks)

5) A company produces components in computer printers. A production supervisor wants to predict the total volume of component production based on the number of hours that trained technicians spend in the assembly process. A plot of the relationship between the number of components assembled and the time spent on assembly is shown below together with Excel output from a regression analysis. It is based on 24 observations

Regression Statistics

R Square

0.978

Observations

24

 

Coefficients

Standard Error

t Stat

P-value

Intercept

4.06

4.85

0.84

0.41

Time

60.40

1.92

31.47

8.69E-20

Write the equation of the regression line

Predict the number of components assembled if time is 2.2 hours

Test the claim the slope is 0, given that the test stat has a t-distribution with df=22

(4 marks)

6)A survey of the selling price of homes in Sydney and Melbourne gave the sample statistics shown in the table below.. Is there sufficient evidence to indicate there is a difference in mean selling price between Sydney and Melbourne? Explain. [To gain full marks you must test the claim, state the hypotheses, choose an appropriate test statistic and write your conclusion.]

Mean

Standard deviation

Sample size

Sydney

$525,000

$5000

25

Melbourne

$529,000

$6000

25

(6 marks)

7) A very wealthy individual considers many requests to donate to charity. The regression output below investigates the relationship between the amount donated and the days required to evaluate the claim. It is based on 19 observations

Regression Statistics

R Square

0.00502

Observations

19

 

Coefficients

Standard Error

t Stat

P-value

Intercept

34.90

3.2155

10.8526

4.61E-09

Amount

0.01

0.0437

0.2928

0.77

Write the equation of the regression line

Predict the days to evaluate if amount is 80

(C)Test the claim the slope is 0, given that the test stat has a t-distribution with df=17 (4 marks)

8) What would be the expected values if we were going to do a hypothesis test of independence on the following data

 

 

beer preference

 

 

 

 

 

light

regular

dark

total

gender

male

20

40

20

80

female

30

30

10

70

 

total

50

70

30

150

(1mark) - note that you only get 1 mark for this question because you only have to do 1 thing, find the expected values

1)Fill ...