Stats question: In a large population of high school students, 20% have experienced math anxiety. You take a random sample of 10 students from this population. The standard deviation of the number of students in the sample who have experienced math anxiety is:
.0160
.2070
.2530
1
1.265

Question

Stats question: In a large population of high school students, 20% have experienced math anxiety. You take a random sample of 10 students from this population. The standard deviation of the number of students in the sample who have experienced math anxiety is:
.0160
.2070
.2530
1
1.265

mathmale · Answer

This problem involves population proportions, not averages.  

You are told that the population mean is 0.20 (which is equivalent to 20%), and we can assume that the population is normally distributed.  There is a formula for finding the SAMPLE proportion under these conditions.

Look up "sample proportion standard deviation" for further info about this.  Doing so might immediately uncover the formula you need and want.

anonymous · Answer

I'm not sure what formula to use though...

mathmale · Answer

Have you done an Internet search for  "sample proportion standard deviation" ?
If you find several results, which result (formula) do you think applies to your math problem?

anonymous · Answer

sqrt((p(1-p))/n)?