↑ Let C be the cost (in dollars) to buy B boxes of cereal. Identify the independent variable and the dependent variable. Which variable is the independent variable? B, the amount of boxes of cereal bought C, the cost Which variable is the dependent variable? C, the cost B, the amount of boxes of cereal bought To reduce laboratory costs, water samples from three public swimming pools are combined for one test for the presence of bacteria. Further testing is done only if the combined sample tests positive. Based on past results, there is a 0.006 probability of finding bacteria in a public swimming area. Find the probability that a combined sample from three public swimming areas will reveal the presence of bacteria. Is the probability low enough so that further testing of the individual samples is rarely necessary? ... The probability of a positive test result is