1.A machine produces bolts which are 10% defective. Find the probability that in a random sample of 400 bolts produced by this machine, (a) at most 30 of the bolts will be defective (b) between 30 and 50 of the bolts will be defective (c) between 35 and 45 of bolts will be defective (d) 65 or more of bolts will be defective
2.The mean grade on a final examination was 72, and the standard deviation was 9. The top 10% of the students are to receive A's. What is the minimum grade a student must get in order to receive an A ?
3.How long would it take to fill a 30 yd^3 packer truck that compresses waste to 750 lb/yd^3 if it travels 100 ft between stops at an average of 5mph and it takes 1 minute to load 200 lb of waste at each stop? if each stop services four homes and two collections runs are made per day, how many customers could be provided with once per week service by this single truck(assuming a five-day week)?