Calculating standard deviation.

May 2010
53
1
Altlanta GA
An example of the calculation for the population standard deviation of a set of data is shown. Approximate the population standard deviation for the set { 4 , 5 , 7 , 5 , 6 , 3}, to the nearest tenth.



1.3 is it the Correct Answer
????????????.
 
Feb 2010
1,036
386
Dirty South
An example of the calculation for the population standard deviation of a set of data is shown. Approximate the population standard deviation for the set { 4 , 5 , 7 , 5 , 6 , 3}, to the nearest tenth.



1.3 is it the Correct Answer
????????????.
1.3 is correct
 
Dec 2009
3,120
1,342
An example of the calculation for the population standard deviation of a set of data is shown. Approximate the population standard deviation for the set { 4 , 5 , 7 , 5 , 6 , 3}, to the nearest tenth.



1.3 is it the Correct Answer
????????????.
Hi allsmiles,

just follow the procedure as detailed.

1. Calculate the mean of the six numbers.
2. Calculate the deviations of the six numbers from the mean.
3. Square all the deviations
4. Sum all the squares of the deviations
5. Find the average square by dividing by 6
6. Take the square root

\(\displaystyle \mu=\frac{4+5+7+5+6+3}{6}=\frac{30}{6}=5\)

The deviations are 4-5, 5-5, 7-5, 5-5, 6-5, 3-5

Hence, square these, find the average of the squares and take the square root.

I get \(\displaystyle \sqrt{1.67}=1.2922\), then just round it off, but go through the workings.
 

masters

MHF Helper
Jan 2008
2,550
1,187
Big Stone Gap, Virginia
An example of the calculation for the population standard deviation of a set of data is shown. Approximate the population standard deviation for the set { 4 , 5 , 7 , 5 , 6 , 3}, to the nearest tenth.



1.3 is it the Correct Answer
????????????.
Hi allsmiles,

\(\displaystyle \mu=5\)

From the table, you can conclude:

\(\displaystyle \sigma=\sqrt{\frac{10}{6}}\approx 1.3\)


Edit: ArchieMeade..what he said!