Study the information provided below and answer the questions that follow.

Chief executive officers (CEOs) have long been a focus of organisational research. This emphasis is understandable, given the widespread belief that a firm's top executive has a substantial impact on its performance. Three years ago, the board of directors (BOD) of TMG Ltd and the then incumbent CEO mutually agreed to part ways due to poor financial performance of the business. The new CEO appointed to replace him was mandated by the BOD to initiate an intervention strategy to turn around the business.

As part of a review of the financial performance of the business, a researcher has recently been contracted by the BOD of TMG Ltd to determine whether the intervention strategy introduced three years ago by the current CEO has produced significantly improved outcomes for the business. The BOD wants the quarterly operating profit margin of the business for the past six year to constitute the unit of analysis. Table 4.1, below, shows the quarterly operating profit margin retrieved from the database of the company.

Table 4.1: Quarterly operating profit margin (%) of TMG Ltd over the past six years.

Consecutive quarters of the CEO tenure Quarterly operating profit margin (%)

Previous CEO Current CEO

1 12.5% 8.3%

2 12.7% 8.0%

3 12.1% 10.1%

4 10.6% 10.5%

5 9.6% 10.4%

6 9.8% 10.8%

7 9.2% 11.2%

8 8.8% 11.5%

9 8.6% 10.9%

10 7.8% 11.6%

11 7.5% 12.4%

12 7.6% 13.5%

The statistical analysis of the data will be undertaken using IBM SPSS Statistics version 25.

4.1 State the aim and significance of the study. 4.2 Identify independent and dependent variables underpinning the study. 4.3 Formulate the null and alternative hypotheses for the study. 4.4 Briefly discuss the essence of the assumption of normality in a quantitative data analysis and highlight any THREE means of determining whether the assumption of normality has been met or not. 4.5 Apart from the assumption of normality, identify TWO parametric assumptions that must be met before you would conduct a parametric test for the study. 4.6 Assuming that parametric assumptions are met, specify TWO statistical tests that you could conduct to test the hypotheses formulated in 4.3 and explain why the two tests you have specified are appropriate. 4.7 Assuming that parametric assumptions are violated, specify TWO statistical tests that you could conduct to test the hypotheses formulated in 4.3 and explain why the two tests you have specified are appropriate.