Answer:
3.4
Step-by-step explanation:
Standard deviation of a population is defined as:
σ² = ∑(xᵢ − μ)² / n
The standard deviation of a sample is defined as:
s² = ∑(xᵢ − x)² / (n - 1)
It's not clear which one we have, so let's calculate both.
First, we must find the mean.
μ = (5+12+15+10+12+6+8+8) / 8
μ = 9.5
Now we find the squares of the differences:
(5-9.5)² + (12-9.5)² + (15-9.5)² + (10-9.5)² + (12-9.5)² + (6-9.5)² + (8-9.5)² + (8-9.5)²
= 80
Divide by n:
σ² = 80 / 8
σ² = 10
And take the square root:
σ = √10
σ ≈ 3.2
That's not one of the answers, so let's try the standard deviation of a sample instead of a population.
Instead of dividing by n, we'll divide by n-1:
s² = 80 / 7
And take the square root:
s = √(80/7)
s ≈ 3.4
So that must be it.
Answer:
C 13.3 units
Step-by-step explanation:
The Pythagorean theorem is used to find the distance between two points. On a graph like this, you can count the number of squares between points horizontally and vertically, so can fill in the calculation for the hypotenuse directly from the graph.
... hypotenuse length = √((horizontal distance)² +(vertical distance)²)
... JK = √(2²+2²) = √8 ≈ 2.83
... KL = √(2²+5²) = √29 ≈ 5.39
... LM = √(2²+2²) = √8 = 2.83
... MJ = √(2²+1²) = √5 ≈ 2.23
The perimeter is the sum of these distances around the figure:
... perimeter = JK +KL +LM +MJ
... perimeter = 2.83 +5.39 +2.83 +2.23 = 13.3
We will see that the percentage in which the price decreases is 90%, thus the age is 90 years.
<h3>
</h3>
How old is Andrés?
We know that the percentage in which the price decreases is equal to the age of Andrés.
We can write:
P = $4,000 = $40,000*(1 - k)
Where k is the percentage in decimal form.
Solving for k:
k = ($40,000 - $4,000)/$40,000 = 0.9
To obtain the percentage, we multiply by 100%.
0.9*100% = 90%
We conclude that Andrés is 90 years old.
If you want to learn more about percentages.
brainly.com/question/24554492
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Answer:
18%
Step-by-step explanation:
= ----> cross multiply
504(100) = 2800x
50400 = 2800x
=
18 = x
Commission Rate: 18%
She practiced 630 hours in all because you multiply 18x35