Standard deviation is a measure about how much a number or a value is deviating from the mean of the whole data set. In other words, it tells us how much is data scattered. The formula for calculating the standard deviation is as follows:
Assume that in a class 10 students have scored the following marks in math test: 25, 35, 65, 75, 64, 43, 59, 71, 91 and 32. To calculate the standard deviation, first, calculate the mean.
Then we have to take the squares of the difference between mean and each student’ score.
Scores 
Mean 
Mean  Score 
(Mean  Score)^{2} 
25 
56 
31 
961 
35 
56 
21 
441 
65 
56 
9 
81 
75 
56 
19 
361 
64 
56 
8 
64 
43 
56 
13 
169 
59 
56 
3 
9 
71 
56 
15 
225 
91 
56 
35 
1225 
32 
56 
24 
576 



4112 
Using the above formula the standard deviation will be as follows:
Linda Lechner has just been severely chastised for her inventory policy.
Among the thirty largest U.S. cities, the mean
Estimate the mean and the standard deviation of the following frequency distribution
Using samples of 200 credit card statements, an auditor found the
a. How many variance terms and how many different covariance terms
Frostbite Thermalwear has a zero coupon bond issue outstanding with a face
Stock X has a 10% expected return, a beta coefficient
As part of an insurance company’s training program, participants learn how
Ned’s Natural Foods sells unshelled peanuts by the pound. Historically,
You must analyze a potential new product—a caulking compound that