Please answer question 3 and it's follow up questions, show your work and notations, along with a therefore statement for an excellent review.

5. The Weights of 100 remote control cars at a competition are approximately normally distributed. The average weight is 3.2 kg. with a standard deviation of 0.4 kg. a. How manyr remote-control cars would be disqualied if it were against the rules to have a car with a weight of more than 4 kg or less than 2.4 kg? [41'] b. A car is said to be in the 90'\" percentile. How much does it weigh? [21']