1
$\begingroup$

I want to calculate a standard error of a sample. I have a distribution of the IQ of the general population with a mean of 100 and a standard deviation of 19. Now I take a random sample of 30 students of Harvard and find that their mean IQ is 125.

I want to calculate the standard error of the mean. How can I do this? I cannot use $\sigma \over \sqrt{n}$ because I don't have the sd of my sample or?

Improve this question
$\endgroup$
5
  • 1
    $\begingroup$ You need the sample standard deviation $\hat{\sigma}$ to estimate the standard error. $\endgroup$
    – user2974951
    Commented Sep 26, 2018 at 12:06
  • $\begingroup$ Yes, thats what I thought. We don't have that. Is there another way like bootstrapping? $\endgroup$
    – Jensxy
    Commented Sep 26, 2018 at 12:18
  • $\begingroup$ You can only do bootstrap if you have a sample, which you don't, otherwise you could estimate the SD. $\endgroup$
    – user2974951
    Commented Sep 26, 2018 at 12:20
  • $\begingroup$ I also know that the IQ is normal distributed. That's it. That are all information in the question. $\endgroup$
    – Jensxy
    Commented Sep 26, 2018 at 14:53
  • $\begingroup$ Then you are figuratively screwed. $\endgroup$
    – user2974951
    Commented Sep 27, 2018 at 6:02

0

Reset to default

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.