Answer:
4
Step-by-step explanation:
Divide 5 on both sides, to get x=4
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:
-7.5
Step-by-step explanation:
Simplify
-4b - 5 + 2b = 10
-2b - 5 = 10
-2b = 15
b = -7.5
Answer:
Step-by-step explanation:
C=2πr
18=2×3.14×r
18=6.28r
r=2.88
Arc of a circle
A=®/360°πr
6=®/360°×3.14×r
®=239°
6
Answer:
It's correct!
Step-by-step explanation:
