Find the variance and standard deviation of the given set of data to the nearest tenth.
{440, 130, 280, 500, 150, 640, 760}
a) variance = 222.7, standard deviation = 49,595.9
b) variance = 49,595.9, standard deviation = 24,798
c) variance = 49,595.9, standard deviation = 222.7
d) variance = 57,861.9, standard deviation = 240.5

Part 1) variance = 49,595.9

Part 2) standard deviation = 222.7

Option C

Step-by-step explanation:

we have

set of data

step 1  

Find the mean  

Adds the values and divide by the number of values

In this problem the number of values is 7

step 2  

for each number: subtract the Mean and square the result  

step 3  

work out the mean of those squared differences  

----> this value is called the "Variance"  

step 4

The standard deviation is the square root of the variance

so

The standard deviation is equal to