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.
Area of the base = 1/2 * 10 * 5sqrt3 = 25 sqrt3
Total surface area = 25 sqrt3 + 3 * 1/2 * 10 * slant height = 214.5
25 sqrt3 + 15h = 214.5
15h = 214.5 - 25 sqrt3
h = (214.5 - 25sqrt3() / 15
= 11.41 cm to nearest hundredth
Answer:
$163.85
Step-by-step explanation:
Markup 45% means selling price is 100+45 = 145% of cost
145/100 × 113 = 163.85
