Standard Deviation

[TierDenise]

You select a random sample of n = 14 families in your neighborhood and find the following family sizes (number of people in the family).

15, 16, 16, 15, 19, 16, 18, 15, 17,16, 15,17,16, 18

I found the mean family size which is 16.4. To find the mean family size, I added up all of the numbers listed above and divided the total by 14. That gave me 16.35714286 which I rounded to 16.4. I'm stuck on part B.

b. What is the standard deviation for the sample? (Round to the nearest tenth)

 

[Dason]

Hi! :welcome: We are glad that you posted here! This looks like a homework question though. Our homework help policy can be found here. We mainly just want to see what you have tried so far and that you have put some effort into the problem. I would also suggest checking out this thread for some guidelines on smart posting behavior that can help you get answers that are better much more quickly.

 

[TierDenise]

I found the mean family size which is 16.4. To find the mean family size, I added up all of the numbers listed above and divided the total by 14. That gave me 16.35714286 which I rounded to 16.4. I'm stuck on part B. The standard deviation equation confuses me. I'm about to try and square all of the numbers for the standard deviation.