View Policies Current Attempt in Progress A chemist has a 5-gallon sample of river water taken downstream from the outflow of a chemical plant. He is concerned about the concentration, c (in parts per million), of a certain toxic substance in the water. He wants to take several measurements, find the mean concentration of the toxic substance for this sample, and have a 95% chance of being within 500 parts per million of the true mean value of c. If the concentration of the toxic substance in all measurements is normally distributed with a = 1 100 parts per million, what is the minimum integer number a of measurements needed to achieve this goal? @Textbook and Media Assistance Used Save for Later Attempts: 0 of 3 used Submit AnswerCurrent Attempt in Progress Otto is trying out for the javelin throw to compete in the Olympics. The lengths of his javelin throws are normally distributed with a mean of 310 feet and a standard deviation of 17 feet. What is the probability that the total length of three of his throws will exceed 950 feet? Round your answer to two decimal places. P= eTextbook and Media Save for Later Attempts: 0 of 3 used Submit