In first 40 hours he earns = 7.30 x 40 = $292
Each hour after his rate = 7.20 x 1.5 = $10.80 per hour
In extra four hours he earns = 10.80 x 4 =  $43.20 
Total earnings = $292 + $43.20 = $335.20 
Therefore you don't agree
Hoped this helped you
        
             
        
        
        
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.
 
        
             
        
        
        
No because 7/9= 0.777777777789 and 8/9= 0.888888888888889
        
             
        
        
        
Hahaha anyway thanks for the free point