If the variance of the ages of the people who attended a rock concert is 38, what is the standard deviation of the ages? round your answer to two decimal places

The standard deviation of the age is 6.16

Step-by-step explanation:

* Lets talk about the variance and the standard deviation

- The variance is the measure of how much values in a set of data are

 likely to differ from the mean value of the same data

- The steps to find the variance are:

1- Find the mean of the data  

2- Subtract the mean from each value and square the answer

3- Add all of these squared answer and divide the sum by the number

  of the values

- The answer of the step 3 is The variance (σ²)

- The standard deviation (σ) is the square root of the variance

* Now lets solve the problem

∵ The variance of the ages of the people who attended a rock

  concert is 38

∴ σ² = 38

∵ The standard deviation is the square root of the variance

∴ σ = √38 = 6.16

* The standard deviation of the age is 6.16

Step-by-step explanation:

By definition, the variance V of a population is defined as:

Where is the standard deviation

We know that , then we can solve the equation for the standard deviation

Finally  the standard deviation is:

distance covered by pamela in 9 l of fuel = 99km

let us apply unitary method here.

distance covered by pamela in 1 l of fuel =99/9 =11 km

now let us find distance covered by pamela if she has 12 l of fuel.

distance covered in 12 l = distance covered in 1 l of fuel * 12

we know that distance covered by here in 1 l is 11 km.

so distance covered in 12 l of fuel = 11*12 = 132 km.