iii. 3 marks Instead of using my current sampling methods, design an approriate stratied sampling scheme for this case and discuss how it may be better than a simple random sampling. (b) Air quality is measured by the air quality index (AQI) reported by the Environmental Protection Agency. This index tells you how clean or polluted your air is, and what associated health effects might be a concern for you. The index is calculated for ve major air pollutants regulated by the Clean Air Act, one of which is particulate matter. Values of this index range from D to 300 and a higher value indicates lower air quality. AQI was reported for 90 randomly sampled days in Durham over the past 5 years. The histogram below shows the distribution of these values. These 90 days represent a reasonably random and representative sample, and you may assume that the AQI levels for these days are independent. 18- 1s- 14- 12- count 8121620242832364044455256536468?2 AOI i. Approximate the median AQI value. iii. The average AQI for these 90 days is 39.26, with a standard deviation of 9.13. Determine whether this distribution has any outliers. If yes, note how many outliers there are and their approximate values. (a) I am interested in how students are dealing with remote learning in the class of STAT1008. I plan to design a set of survey questions and post it on Wattle. Students are encouraged to participate in this online survey, but it will not count toward their final grade. Some of the questions include: age, gender, major, number of hours spent in live lectures or lecture recordings, whether or not join live tutorials, etc.. 1. 1 marks What is the population? What is the sample?iv. Under a well designed stratied sampling scheme, what type of survey errors might still arise? Explain. ii. 1What sampling scheme am I using? What is the disadvantage of this sampling method? ii. 4 marks Construct a boxplot for this sample. Use aproximate five-number statistics