The height of your workstation desk is one of the essential criteria for creating the perfect ergonomic workspace, whether at home or in your office. A company's plant manager is currently considering two designs of ergonomic computer desks for their employees. An experiment is performed to help with the purchasing decision. 45 randomly selected employees used the design A computer desk, and another 45 employees used the design B computer desk. On a 15-point scale, their comfort level was recorded in the EXCEL file ErgonomicDeskDesign.xlsx. Use EXCEL and an appropriate hypothesis test to help the plant manager to answer the following research question.

Research Question: Are the comfort levels of the two designs (design A and design B) different?

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DesignA	DesignB
6.1	9.8
4.1	6.2
5.1	7.5
4.8	7.4
6	9.4
6.6	5.8
7.4	8
6.7	7
6	8
7	8.2
4.2	8.3
7.2	8.1
6.1	5.7
6.2	7.6
7.6	7.5
4.9	8.3
6.2	7.5
6.4	7.8
5.7	9.4
3.4	7.5
7.1	7.9
5.2	8.2
6.2	8.2
3.6	7.1
6.2	8.8
5.2	8.2
5.6	7.6
8.5	7.7
6.7	6.8
6.6	7.6
6.1	8.4
6	9.2
6.6	8.2
6.8	6.6
6.3	9.6
6.5	6.4
5.8	10.3
6	8.9
4.1	9.2
5.4	7.7
6.8	9
5.3	6.8
5.1	6.3
7.3	7.6
6.6	7

Answer the following questions by choosing the most correct option or typing the answer:

(1 mark) The most appropriate test for these data is: Answer

(1 mark) Which graphical display would be useful to check normality assumption for this hypothesis? Answer

Figure 1

Figure 2

Figure 3

Figure 4

Figure 1 & 2

Figure 3 & 4

No need to check normality assumption

All four figures are needed

(1 mark) How can you check the assumption of equal variances? Answer Comparative boxplots could be used (e.g. if the sizes of boxes are similar or not)

Descriptive statistics such as variance, standard deviation and range could be used

Descriptive statistics such as mean and median could be used

The histogram of differences could be used

Both A & B could be used

No need to check the assumption of equal variances

For the remaining questions you may assume that any relevant assumptions have been met.

(2 marks) The absolute value of the test statistic is equal to Answer (3dp)

(1 mark) The degrees of freedom is equal to Answer (Integer)

(1 mark) The p-value is larger than 0.05 Answer

(2 marks) The test shows that the comfort level ratings were Answer

A. significantly different between design A and design B, possibly greater for design A.

B. significantly different between design A and design B, possibly greater for design B.

C. not significantly different between the two design of the computer desks.