Question 248008: The Math SAT scores for women are normally distributed with a mean of 496 and a standard deviation of 108, if five math SAT scores are randomly selected from the population of women who take the test, find the probability that all five scores are above 500
There was a part b to the question: if a woman who takes the math portion of the SAT is randomly selected, find the probability that her score is above 500..... for this I got P(x>500>= .4852
by using my calculator normal cdf (500,1E99, 496,108)
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! The Math SAT scores for women are normally distributed with a mean of 496 and a standard deviation of 108,
If five math SAT scores are randomly selected from the population of women who take the test, find the probability that all five scores are above 500
------
Your part b gives the probability that one women has a score above 500.
Assuming independence the probability of 5 having a score above 500
should be (0.4852)^5 = 0.0269.
My previous answer gave the probability that the sample mean would be
above 500. Sorry about that.
====================================================================
There was a part b to the question: if a woman who takes the math portion of the SAT is randomly selected, find the probability that her score is above 500..... for this I got P(x>500>= .4852
by using my calculator normal cdf (500,1E99, 496,108)
----
Good, because you used the population standard deviation (108).
If part "a" I used the standard deviation of the sample means
which is 108/sqrt(6).
================================
Cheers,
Stan H.
|
|
|
