Assignment

Problem 2 (25 pts)

Consider the sample data for plants A, B, C & D of the above company, which are

tabulated in table 1. Test whether the four means are equal at the 5% level of significance. Perform a test that will compare all 4 means at once. We are not interested in pair-wise comparisons at this stage. Please show all the steps in your calculations.

Table 1:

A    B    C    D 333 328 320 333

332 329 321 321

320 323 322 329

326 327 325 330

328 330 326 328

325 331 328 325

323 332 329 333

321 320 330 331

334 324 331 327

322 323 332

320 334

329

330

328

331

330

Problem 3 (25 pts)

The camera store in question wants to increase sales and is exploring three options:

1.      Invest and expand the current store.

2.      Open a second store in another part of the city.

3.      Open an online outlet.

Develop a methodology including the statistical methods used to assess between these options.

Problem 4 (25 pts)

Read the article (p. 221 – 225)

«Performance and duration differences between online and paper–pencil tests» and answer the questions below.

Part A.

1.  Develop a 95% confidence interval using data from this study.

2.  Perform a hypothesis testing using data from this  study. (show all the the appropriate steps).

3.  Suggest another statistical technique(s) for the purpose of this study. Explain.

Part B.

For this study briefly describe how the researcher draw conclusions from a sample about a population. Try to be as analytic as possible and use the comments bellow.

1.  Determine (or define) the independent variable(s).

2.  Determine (or define) the dependent variable(s).

3.  Determine (or define) qualitative and quantitative variable(s).

4.  Determine (or define) the sample and the population.

5.  Describe the statistical method(s) being used and define inferential statistics. Interpret the meaning of p-value.