The lengths of pregnancies are normally distributed with a mean of 269 days and a standard deviation of 15 days. a. In a letter to an advice column, a wife claimed to have given birth 308 days after a brief visit from her husband, who was working in another country. Find the probability of a pregnancy lasting 308 days or longer. What does the result suggest? b. If the length of pregnancy is in the lowest 4%, then the baby is premature. Find the length that separates premature babies from those who are not considered premature. a. The probability that a pregnancy will last 308 days or longer is (Round to four decimal places as needed.)

50 part-time students were asked how many courses they were taking this term. The (incomplete) results are shown below:  # of Courses Frequency Relative Frequency Cumulative Frequency 1 13     2 22     3       4 5       a. Complete the table above b. Find the sample mean and sample standard deviation. c.  How many standard deviations above or below the mean is taking three classes? d. Find the probability that someone takes at least 3 classes.

The lengths of pregnancies are normally distributed with a mean of 270 days and a standard deviation of 15 days. a. In a letter to an advice column, a wife claimed to have given birth 309 days after a brief visit from her husband, who was working in another country. Find the probability of a pregnancy lasting 309 days or longer. What does the result suggest? b. If the length of pregnancy is in the lowest 3%, then the baby is premature. Find the length that separates premature babies from those who are not considered premature. a. The probability that a pregnancy will last 309 days or longer is (Round to four decimal places as needed.) What does the result suggest? OA. The result suggests the event did not occur. OB. The result suggests that the husband is the father. C. The result suggests an uncommon but not significant event occurred. OD. The result suggests that either a very rare event occurred or the husband is not the father. b. Babies who are born on or before ☐ days are…

The lengths of pregnancies are normally distributed with a mean of 269 days and a standard deviation of 15 days. a. In a letter to an advice column, a wife claimed to have given birth 308 days after a brief visit from her husband, who was working in another country. Find the probability of a pregnancy lasting 308 days or longer. What does the result suggest? b. If the length of pregnancy is in the lowest 2%, then the baby is premature. Find the length that separates premature babies from those who are not considered premature. a. The probability that a pregnancy will last 308 days or longer is ☐ (Round to four decimal places as needed.)