A detection device is used to monitor the level of carbon monoxide (CO) in the air. the following data, i ppm (parts per million) were collected from various locations inside a recreation facility. (7.28, 8.50, 5.56, 8.18, 4.03, 6.98, 9.13, 7.34, 5.56, 8.69, 9.05, 7.98} Questions: a) Identify the variable in this data. Be specific. (2pts) b) Is the variable discrete or continuous? c) Compute the sample mean, median, and sample standard deviation rounded to 3 decimal places. Work is not needed. d) Find a 99% confidence interval for the population mean carbon monoxide level in the air in this location. Identify the calculator function that you are using and then write the answer (3 decimal places) in the format: lower boundary