Work: This must be done using a graphing calculator. For this answer, I will be using terms from the TI-84 graphing calculator. You start by navigating on the calculator to the statistics section in which you will be able to find the normalcdf function. The functions asks you for the mean, which is 750, the standard deviation, which is 50, and the upper and lower bounds of the probability. Since the question asks for the probability that scores higher than 850, 850 will be the lower bound and 1E99 will be the upper bound. 1E99 is essentially infinity, so this will give you the most accurate answer possible. Once you plug these values into the calculator, you let the machine do the rest of the work. The calculator will output the value 0.0228. This is your answer.
First, you need to get to one gallon, which is 37.20 divided by 12. (3.1) Divide that number by four, which is: 0.775, or 0.78 rounded up to the nearest hundredth. Hope that helped.
