The length of human pregnancies from conception to birth is known to be normally distributed with a mean of 266 days and standard deviation of 16 days. A pregnancy longer than "nine months" might be considered as 274 days or longer (four months have 30 days, and February has 28 in most years). What proportion of pregnancies last more than "9 months?" First, find the z-score for 274: (274- 266)/16 =0.5. Then, find the area to the of 0.5, using the table.
Continuous Probability Distributions
Probability distributions are of two types, which are continuous probability distributions and discrete probability distributions. A continuous probability distribution contains an infinite number of values. For example, if time is infinite: you could count from 0 to a trillion seconds, billion seconds, so on indefinitely. A discrete probability distribution consists of only a countable set of possible values.
Normal Distribution
Suppose we had to design a bathroom weighing scale, how would we decide what should be the range of the weighing machine? Would we take the highest recorded human weight in history and use that as the upper limit for our weighing scale? This may not be a great idea as the sensitivity of the scale would get reduced if the range is too large. At the same time, if we keep the upper limit too low, it may not be usable for a large percentage of the population!
![The length of human pregnancies from conception to birth is known to be normally distributed with a mean of 266 days and a standard deviation of 16 days. A pregnancy longer than "nine months" might be considered as 274 days or longer (four months have 30 days, and February has 28 in most years). What proportion of pregnancies last more than "9 months?" First, find the z-score for 274: (274 - 266)/16 = 0.5. Then, find the area to the _____ of 0.5, using the table.
Your answer: __________
**Need help on this question?**
- [Read the ebook page on this topic (no penalty)]
- [Get a hint (fewer points)]
- [Show answer (no points)]](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F2fb7a5f7-d1fe-47c3-ab51-c010c8f81dff%2Fe2bfde58-80e2-41f4-a800-211e4c8b62be%2F5yj0y9_processed.jpeg&w=3840&q=75)
Trending now
This is a popular solution!
Step by step
Solved in 2 steps with 1 images
