# NCE: how to find population mean/variance/standard error

#### nijm

##### New Member
I have been given a homework problem with NCE with an average score of 100, and individual's score of 130.
Can anyone guide me to a resource that will help me figure the sample mean, SD, Sample variance, population mean, standard deviation of population, population variance, and standard error?

I am unsure how to find these calculations without a normal data set.

#### nijm

##### New Member
yes the NCE is the normal curve equivalent?

This is the question:
Mary's parents have her tested for everything, including her IQ. Mary's IQ was tested at 130. Assuming a NCE with an average score of 100, they compare Mary's scores to the mean using a z-test.

#### Junes

##### Member
Hmm. That doesn't seem like it's actually an NCE score as I understand it from the Wikipedia page (which ranges from 0-100), but rather a normal distribution with mean 100.

Note that many IQ tests are constructed to have an SD of 15.

But I still don't see an actual question in here?

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#### nijm

##### New Member
Sorry, the professor is asking us to find the population mean, sample mean, standard deviation of the sample score, standard deviation of the population, population variance, and standard error of the sample from the score and NCE of 100.