A very sensitive and essential chemical reaction required to break down a radioactive compound is approximately normally distributed with a mean time of 180 seconds and a standard deviation of 5.2. (a) What time would result in a z-score of 1.5? (b) A time that is shorter than 170 seconds or longer than 192 seconds will discarded. What is the probability that a reaction will need to be discarded? (Note: Round your answer to four decimal places.)