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:
x = -2 & y = 6
Step-by-step explanation:
Hope this helps.
Answer:
a =12*sqrt(2)
Step-by-step explanation:
3. The Pythagorean theorem states
a^2 + b^2 = c^2 where a and b are the legs and c is the hypotenuse
a^2 +21^2 = 27^2
a^2 +441 =729
Subtract 441 from each side
a^2 +441-441 = 729 -441
a^2 =288
Take the square root of each side
sqrt(a^2) = sqrt(288)
sqrt(xy) = sqrt(x)sqrt(y)
a = sqrt(144)sqrt(2)
a =12*sqrt(2)
Answer:
A
Step-by-step explanation:
This sentences implies that to a number multiplied by 3 ( three times a number) 14 needs to be subtracted.
