Answer Happy

B. Problem Solving 1. ABC Company manufactures special bulbs for underground use and claims that the average life of the bulb is 1200 hours. ISM Company is willing to buy a very large quantity if the claim is true. A random sample of 113 bulbs is tested, and it is found out that the sample mean is 1,215 hours with a standard deviation of 100, Set 10, Is it likely that the bulbs will be bought? 2. A study conducted showed that the average total monthly expenditure of SPSPS students is P4,292 a month. ABC analyst believes this figure is too high and decides to conduct her survey by randomly selecting 55 students and found that the average expenditure is P4,008, with a standard deviation of P386. Using the sample results and a = -01, test to determine whether the figure published by the first study is too high