posted by James on .
Find the 35th percentile of the normal distribution with mean 270 and SD 25.
Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability (.35) and its Z score.
Insert in equation above and solve for score.
Hi Psy, thanks for the input. I am having difficulties finding the Z score. I found some Z tables online and looked up the valor for Z = 0.35 but the answer (for the z score) is always bigger than the mean, which I am finding quite odd. Would you mind detailing the process a bit more? I know it should be simple but it's my first time doing Stat :( Thanks in advance.
(find the 35th percentile from the normal curve and then convert into standard units. you will find the link to normal curve at the top of the page. there you will get z)
I think you should read the last lecture of lecture 5. It just shows you how to solve. Much better. Don't waste your time posting stuff here to which no one will respond.Plus, there will be someone telling you about the honor code.
It's fun to do these actually! Try them, and you'll definitely get it.
All the best!!