The probability of a memory chip from a production line being defective is 0.04. Find the probability that, in a sample of 8 chips, there are 2 defectives. Use a suitable approximation to find the probability that, in a sample of 200 chips, thereare7 defectives. A different production line has 15 defectives in a sample of 40. Find a 95% Confidence Interval for the proportion of defectives coming off the production line.