1. ## Random Sampling

If the heights of female nurses at a certain hospital follow a normal distribution with the mean = 173cm and standard deviation = 10cm, in a random sample of 500 adult female nurses, how many would you expect to be below 150cm tall?

using the above population, what proportion of females have heights above 160cm?

a normal distrubution has an interquartile range of 10. if the mean is 50, find the value of the lower quartile.

Not sure how to put this question together, would it be in a standard normal curve or something else?

Thanks

2. ## Re: Random Sampling

Originally Posted by Smiggle12
If the heights of female nurses at a certain hospital follow a normal distribution with the mean = 173cm and standard deviation = 10cm, in a random sample of 500 adult female nurses, how many would you expect to be below 150cm tall?

using the above population, what proportion of females have heights above 160cm?

a normal distrubution has an interquartile range of 10. if the mean is 50, find the value of the lower quartile.

Not sure how to put this question together, would it be in a standard normal curve or something else?

Thanks
For the first part you start by finding the probability p(H<150) that a random nurse is taller than 150cm. You do this by observing that Z=(H-173)/10 is a standard normal random variable. Then the expected number below 150 cm is 500*p(H<150).

CB