1) A large industrial complex would like to design a schedule for changing its light bulbs. For proper lighting, it is essential that the bulbs be changed prior to burning out. In order to develop the schedule, the company models the bulbs' useful lifetime using a normal distribution. They know from past experience that on average bulbs will last 1700 hours before burning out and they estimate that the standard deviation to be 150 hours. Safety regulations require that no more than 20% of the bulbs be burned out at any given time. To be on the safe side, the company would like to change them so that no more than 15% burn out before they are changed. After how many hours of use should the bulbs be changed in order to meet this goal? 2) A new drug is being tested to see whether it can reduce the diastolic blood pressure measurement for adults age 45-60 years. The upper limit for diastolic blood pressure measurement should be 90 mmHg. A. H\": p 90 mmHg 3) A large industrial complex would like to design a schedule for changing its light bulbs. For proper lighting, it is essential that the bulbs be changed prior to burning out. In order to develop the schedule, the company models the bulbs' useful lifetime using a normal distribution. They know from past experience that on average bulbs will last 1700 hours before burning out and they estimate that the standard deviation to be 150 hours. One proposal is to change the bulbs every 1620 hours (about every 90 days). If that plan is used, what percentage of lightbulbs will burn out before they are changed