Suppose that a commercial bakery produces chocolate chip cookies. Based on extensive testing, the bakery has determined that the ideal number of chocolate chips per cookie is 18. In the past, master bakers mixed the dough and spooned it onto sheet pans by hand, but the owners have decided to test a new machine. The machine extrudes dough onto baking sheets at a uniform rate. It runs continuously from 4:30 a.m. until 12:30 p.m. The number of chips per cookie depends on the viscosity of the dough, and because the dough stiffens as it sits in the machine, the machine produces cookies that contain the optimal number of chips, 18 per cookie, between the hours of 5:00 a.m. and 11 a.m. The distribution of cookies is shown in the graph below

A student is concerned with the amount of air pollution students are exposed to in the school's parking lot after school. The student conducts an investigation to compare the quantity of particulate matter released from the diesel-powered buses, natural gas-powered buses, and the large and small cars as they idle waiting to pick up students. To make measurements, a small piece of white fabric is used to collect particulate matter from the tailpipe of each vehicle as it idles for five minutes. Each piece of fabric is then analyzed to measure the amount of particulate matter it collected. (i) Identify the independent variable in the investigation. (j) Identify one variable that was not mentioned in the description that could affect the results of the investigation. (k) Describe a realistic alternate sampling method to collect particulate matter from the vehicles in the investigation. (1) The student wants to ensure that the results are reliable. Explain how the student could modify the…