BUS105: Statistics

The COVID-19 pandemic had changed the working lifestyle of many people. The work-from-home policy had caused most workers to be more sedentary. We sit hours and hours in front of our computers and often in less than ideal postures. Anyone with common sense will know this is going to affect our health. In fact, it will shorten our life quite substantially! According to a longitudinal study, sedentary lifestyle is linked to double mortality risk (European Society of Cardiology, 2019).

Therefore, no one can dispute the fact that exercising is beneficial to health. The question is how much exercise is considered enough? It turns out that medical and fitness experts provided a wide range of answers. The HealthXchange.sg had provided a tip on this based on the guidelines from the World Health Organisation.

It mentioned that ‘adults should do at least 150 minutes of moderate-intensity aerobic physical activity a week.’ (Chumari, n.d.) However, a recent article in The New York Times (Reynolds, 2020) reported that ’11 minutes of exercise a day may help counter the effects of sitting’.

Of course, the sweet spot is about 35 minutes of moderate activities per day. The interesting point to note is there was similar research done in 2016 and the recommendation was 60 to 75 minutes of moderate exercise per day (University of Cambridge, 2016). So, why was there such a large difference given that it was similar research?

It turns out that the difference is in the methodology of data collection (Reynolds, 2020). In the 2016 research, people were asked to recall their activity and sedentary time. Unfortunately, humans are unreliable in narrating their life. They tend to overestimate physical activity and underestimate their sedentary time.

In the 2020 research, many authors of the 2016 reviews decided to repeat the study but with the participants wearing activity monitors. This research provided a more accurate result which was drastically different from the earlier report. Being a sharp student in Statistics, you picked up on the important point of accurate data collection methodology. You decided to try it out on your coursemates.

Initially, you have asked 100 coursemates to give an estimate of their average sedentary time in a day. Thereafter, you asked them to wear an activity monitoring device and calculated their average daily sedentary time objectively. The recordings were found in the dataset provided.

Question 1

(a) Describe the central tendency of average daily sedentary time for both measurements using relevant Excel reports. Determine the standard deviation and interquartile range of average daily sedentary time for both measurements and explain how you decide on the appropriate use of the two measures of dispersion.

(b) Using appropriate charts and numerical measures, develop a summary report to address the issue of human tends to underestimate their sedentary time. You are expected to provide interpretation to the charts and numerical measures. You are not required to do any further inferential analysis. The word limit is 300 words. Please indicate the word count at the end of your answer.