# Standard Deviation...

• Nov 23rd 2007, 08:44 AM
leaaa
Standard Deviation...
Hi All,

Im really stressed =[

I have started my Business IT degree at Uni and I have a module on 'Statistics and Data Analysis' for the first Semester.

I just have to get past this exam and then I dont have to worry about it again!

The problem is though, although I did really well on my GCSEs I done very badly in Maths. My ALevels did not consist of anymaths at all so its been a while!

I'm struggling so much with Standard Deviation.

The teacher has given me the typical equation, but he has (n-1) underneith the equation.

When I look online I cant find why he has this.

It just has n on the normal standard deviation equation.

Can someone tell me if n always equals to 10? or does it equalto the number of values you have?? As all of the practice questions state n as 10.

I have explained to my lecturer that i need extra support but our class is too big so he has no tmie to fully explain things to me..

Can anyone help? x
• Nov 24th 2007, 12:55 AM
CaptainBlack
Quote:

Originally Posted by leaaa
Hi All,

Im really stressed =[

I have started my Business IT degree at Uni and I have a module on 'Statistics and Data Analysis' for the first Semester.

I just have to get past this exam and then I dont have to worry about it again!

The problem is though, although I did really well on my GCSEs I done very badly in Maths. My ALevels did not consist of anymaths at all so its been a while!

I'm struggling so much with Standard Deviation.

The teacher has given me the typical equation, but he has (n-1) underneith the equation.

When I look online I cant find why he has this.

It just has n on the normal standard deviation equation.

Can someone tell me if n always equals to 10? or does it equalto the number of values you have?? As all of the practice questions state n as 10.

I have explained to my lecturer that i need extra support but our class is too big so he has no tmie to fully explain things to me..

Can anyone help? x

n is usually the sample size for normal distribution questions.

RonL