1. The J.O. Supplies Company buys calculators from a Korean supplier. The probability of a defective calculator is 20%. If 14 calculators are selected at random, what is the probability that less than 3 of the calculators will be defective?
2. An important part of the customer services responsibilities of a cable of company relates to the speed with which trouble in service can be repaired. Historically, the data show that the probability is 0.30 that troubles in a residential services can be repaired on the same day. For the first fifteen troubles reported on a given day, what is the probability that 7 or more troubles will be repaired on the same day?
3. Given the length an athlete throws a hammer is normal random variable with mean 60 feet and standard deviation 4 feet, what is the probability he throws it between 55 feet and 62 feet?
4. If x is a binomial random variable where n=150 and p=0.4, find the probability that X is more than or equal to 55 using the normal approximation to the binomial.