(Q7.2.a) A study found that the mean amount of time cars spent in drive-throughs of a certain fast-food restaurant was 138.7 seconds. Assuming drive-through times are normally distributed with a standard deviation of 28 seconds, complete both parts below, rounding to four decimal places. For each answer, give the answer and explain how you found it - you can use the table of values or a calculator command -- just say what you did, step by step, to get your answer. (a) What is the probability that a randomly selected car will spend more than 180 seconds in the restaurant's drive-through? (b) Would it be unusual for a car to spend more than 3 minutes in the restaurant's drive- through? Why