You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
probability
- Thread starter almill21
- Start date
showing work
so far this is what I got: by using x=mean+z(sd) so 650=510+z(1000) => z=0.14 => x=0.5557 so 1-0.5557=0.4443=44.43% will score over 650 , I was wondering if this method is correct, if not could someone point out the right steps and possibly give a final answer so that I can verify for both. thank you very much --Alex
so far this is what I got: by using x=mean+z(sd) so 650=510+z(1000) => z=0.14 => x=0.5557 so 1-0.5557=0.4443=44.43% will score over 650 , I was wondering if this method is correct, if not could someone point out the right steps and possibly give a final answer so that I can verify for both. thank you very much --Alex
probability
question: Scores on a nationwide college entrance examination follow a normal distribution with a mean of 510 and a standard deviation of 100. Calculate the probability that a student will score over 650? less than 250?
Method is good, but silly error in calculating z.so far this is what I got: by using x=mean+z(sd)
so 650=510+z(1000) => z=0.14 => x=0.5557 ..OOPS, standard deviation is 100, not 1000
so 1-0.5557=0.4443=44.43% will score over 650 ,
I was wondering if this method is correct, if not could someone point out the right steps and possibly give a final answer so that I can verify for both. thank you very much --Alex
Look up F(z) for z=1.4 instead of 0.14.