Answer:
583
Step-by-step explanation:
The mean of a data set is the average of the data set. It can be found by adding up all of the values and then dividing by the total number of values added. In this case, one is given the mean, and one needs to find a missing value. Since there is a missing element, add one to the total number of values in the data set. The missing element is represented by the parameter (x). Set up an equation and solve:

Simplify,

Inverse operations,

Answer:
It should be A & D
Step-by-step explanation:
These two are the only ones that have the exact same numbers on all three sides. They are congruent based on SSS.
Answer:
a) = 8
Step-by-step explanation:
You add up all the numbers then divide that number by how many numbers you had. 4+5+7+11+13=40 40/5.
Do you want the rest?
Answer:
QR = 82.38 to nearest hundredth.
Step-by-step explanation:
As they are similar corresponding sides are in the same ratio.
So MN / QR = LM / QR
13/51 = 21/ QR
`3QR = 51*21
QR = 51*21/13
QR = 82.38