Question 5. The length of a pregnancy is normally distributed with a mean of 268 days and a standard deviation of 15 days. You select a sample of 36 pregnancies. (a) Find the probability that the sample mean length is less than 268 days. Round your final result to 4 decimal places. (3 points)
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Problem#5 (12 points) The lengths of pregnancies for women are normally distributed with a mean of 268 days and a standard deviation of 15 days. a) If one pregnant woman is randomly selected, find the probability that her length of pregnancy is less than 260 days b) For a random sample of 25 women find the probability that their lengths of pregnancy have a mean that is less than 260 days c) From a random sample of 5 women find the probability that exactly 2 of them have a length of pregnancy shorter than 260 days
Madhur L.
The lengths of pregnancies are normally distributed with a mean of 268 days and a standard of deviation of 15 days. If a sample of 81 women are randomly selected, Find the probability that they have a mean pregnancy less than 265 days. Find the probability that they have a mean pregnancy between 268 days and 270 days.
Lien L.
The length of human pregnancies is approximately normally distributed with mean μ = 266 days and standard deviation σ = 16 days. (a) What is the probability a randomly selected pregnancy lasts less than 260 days? (b) What is the probability that a random sample of 50 pregnancies has a mean gestation period of 260 days or less? (c) What is the probability a random sample of size 15 will have a mean gestation period within 10 days of the mean? (d) At least how many days should the longest 25% of all pregnancies last?
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