Problem 8a

At a 5 % level of significance, conduct a right-tailed test of hypothesis involving two population means defined as follows. The first population mean relates to the mean of those values of Variable 6 that have the attribute represented by the "1" code for Variable 1. The second population mean relates to the mean of those values of Variable 6 that have the attribute represented by the "2" code for Variable 1. Use the pooled variance option when conducting this test. In your answer make sure that you show H0 and Ha, sketch the sampling distribution showing the critical value(s) and the rejection region. Use your calculator to make all the required computations including the test statistic and also state the decision and conclusion in the context of your survey. Show all your work. Where relevant, keep all your work and your final answer to a minimum of four decimals, unless otherwise stated. [10 marks]

Income (Variable 6)

2200

2500

4500

4000

4000

4000

4000

5000

6000

3000

3500

4000

4500

5000

6000

4800

4200

6000

1500

1500

Gender (Variable1) 1= female, 2= male

1

1

1

1

1

1

1

1

1

1

2

2

2

2

2

1

1

1

1

1

Problem 8b

What assumptions did you make in conducting the test in Problem 8a above. Identify ALL key assumptions and fully explain. [4 marks]