To compute the mean, you simply have to sum all the elments in the data set and the divide the sum by the number of elements:

To compute the variance, we first need to compute the distance of each element from the mean. To do so, we build a "parallel" dataset, given by the difference of every value and the mean:


Now we need those difference squared:

The variance is the mean of this new vector, so

Finally, the standard deviation is simply the square root of the variance, so you have

Answer:
Option 4.∠ERT and ∠MRC
Step-by-step explanation:
Definition of vertical angles : The angles opposite each other when two lines cross. They are always equal.Vertical" refers to the vertex (where they cross).They are also called vertically opposite angles.
Option 1. ∠KRC and ∠CRH
Refer the figure .
These angles does not satisfy the definition of vertical angles . since these angles are not opposite.
Option 2. ∠KRE and ∠ERT
These angles does not satisfy the definition of vertical angles . since these angles are not opposite.
Option 3. ∠MRC and ∠KRM
These angles does not satisfy the definition of vertical angles . since these angles are not opposite.
Option 4.∠ERT and ∠MRC
MT and EC are the two lines that cross each other at vertex R ,
Thus ∠ERT and ∠MRC are opposite to each other .
Hence ∠ERT and ∠MRC are pair of vertcal angles .
Answer:
How I do you should get 3.00$/min
Step-by-step explanation:
You see I subtracted 19.50 - 16.50 and then got 3
The Factorization of 121b⁴ − 49 is (11b^2 + 7)(11b^2 - 7).
The equation 121b⁴ − 49
To find the Factorization of 121b⁴ − 49.
<h3>
What is the factor of a^2-b^2?</h3>
The factor of a^2-b^2 is (a+b)(a-b)
We have write the given equation in the form of a^2-b^2

Therefore the factor of the 121b^4 − 49 is (11b^2 + 7)(11b^2 - 7).
To learn more about the factor visit:
brainly.com/question/25829061