Question 6The following data represent ozone readings, in parts per million (ppm),taken at 3:00 p.m.

Question 6The following data represent ozone readings, in parts per million (ppm),taken at 3:00 p.m. for a random sample of 18 days.12, 34, 8, 15, 11, 18, 10, 21, 12, 13, 14, 17, 4, 8, 20, 9, 40, 21a.(4 marks)Construct a stem-and-leaf display for these data. Place the leaves in ascending order.b.(2 marks)In what direction, if any, are the data skewed?c. (2 marks)Calculate the mean ozone reading.d.(5 marks)Calculate the standard deviation of ozone readings. Use the short-cut formula.