How to find variance and std dev in R?

How to find variance and std dev in R?

How to find variance and std dev in R?

This recipe helps you find variance and std dev in R


Recipe Objective

How to find variance and standard deviation in R? Variance is the amount of variation/spread in a data set. The standard deviation is the square root of the variance. Standard deviation and variance are needed for conducting many different statistical tests like to calculate the z-score , t-score etc. This recipe illustrates an example of finding variance and standard deviation.

Step 1 - Define a vector

a <- c(5,10,15,20,25,30)

Step 2- Calculate the mean

print(mean(a)) #using mean()
"Output is ": 17.5 

Step 3 - Calculate the variance

print(var(a)) # using var()
"Output is ": 87.5

Step 4- Calculate the standard deviation

print(sd(a)) # using sd()
"Output is ": 9.354143

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