ACTIVITIES/ASSESSMENTS: 5. The length of life of an instrument produced by a machine has a normal distribution with a mean of 12 months and standard deviation of 2 months. Find the probability that an instrument produced by this machine will last A. less than 7 months. B. between 7 and 12 months. Be sure to draw a normal curve with the area corresponding to the probability shaded. 6. The lengths of human pregnancies are approximately normally distributed, with mean # = 266 days and standard deviation s = 16 days. What proportion of pregnancies lasts more than 270 days? B. What proportion of pregnancies lasts less than 250 dave? C. What proportion of pregnancies lasts between 240 and 280 days? D. What is the probability that a randomly selected pregnancy? lasts more than 280 days? Be sure to draw a normal curve with the area corresponding to the probability shaded