SOLUTION: Below are the times (in days) it takes for a sample of customers from Jack's computer store to pay their invoices. 26, 35, 37, 41, 31 Find the standard deviation of this sample

Algebra ->  Probability-and-statistics -> SOLUTION: Below are the times (in days) it takes for a sample of customers from Jack's computer store to pay their invoices. 26, 35, 37, 41, 31 Find the standard deviation of this sample       Log On


   

Question 1143169: Below are the times (in days) it takes for a sample of customers from Jack's computer store to pay their invoices.
26, 35, 37, 41, 31
Find the standard deviation of this sample of times. Round your answer to two decimal places.
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

given:
26, 35, 37, 41, 31
find mean :
%2826%2B35%2B37%2B41%2B31%29%2F5=170%2F5=34

find the variance, subtract the mean from each of the+x values:
x%5B1%5D=26-34=-8
x%5B2%5D=35-34=1
x%5B3%5D=37-34=3
x%5B4%5D=41-34=7
x%5B5%5D=31-34=-3
Now square all the answers you have got from subtraction.
%28-8%29%5E2=64
1%5E2=1
3%5E2=9
7%5E2=49
%28-3%29%5E2=9
add all the squared numbers:
64%2B1%2B9%2B49%2B9=132
divide the sum of squares by %28n-1%29 , in your case n=5
132%2F%285-1%29=132%2F4=33
so,the variance is 33
find the square root of variance to find the standard deviation delta:
delta=sqrt%2833%29≈5.75