Answer:
Design 3: An SRS of size 3000 from a population of size 300,000,000
Step-by-step explanation:
To check the SRS designs will give the most precision (smallest standard error) for estimating a population mean, we'll make use of the following formula:
V(y) = S²/n( 1 - n/N)
Where S² is a constant for the three SRS designs
Check the first design
n = 400
N = 4000
So, V(y) = S²/400 (1 - 400/4000)
V(y) = S²/400(1 - 0.1)
V(y) = 0.0025S²(0.9)
V(y) = 0.00225S²
V(y) = 2.25S²E-3
The second design
n = 30
N = 300
So, V(y) = S²/30 (1 - 30/300)
V(y) = S²/30(1 - 0.1)
V(y) = S²/30(0.9)
V(y) = 0.03S²
V(y) = 3S²E-2
The third design
n = 3,000
N = 300,000,000
So, V(y) = S²/3,000 (1 - 3,000/300,000,000)
V(y) = S²/3,000(1 - 0.00001)
V(y) = S²/3,000(0.99999)
V(y) = 0.00033333
V(y) = 3.33S²E-4
Answer:
<h2>$503.5</h2>
Step-by-step explanation:
let the apprentice duration of work be x hours
so that the electrician worked (x+4)hours
53*(x+4)+22*x=624.50
opening the bracket we have
53x+212+22x=624.50
collect like terms we have
53x+22x+212=624.50
75x+212=624.50
75x=624.50-212
75x=412.5
divide both sides by 75 we have
x=412.5/75
x=5.5
The electrician worked a total of (x+4)
5.5+4=9.5 hours or 9hours 30min
given that the electrician earns $53 per hour
then,for the work he would make 53*9.5=$503.5
Answer:
Step-by-step explanation:
so he worked 132 hrs in 4 weeks..he worked 6 days per week....
6 * 4 = 24 days...so he worked 132 hrs in 24 days
132 / 24 = 5.5 (or 5 1/2) hrs per day <===
Answer:
1 Cookie = $6
Step-by-step explanation:
6/36 = 1 cookie for $6
Answer:
5 minutes
Step-by-step explanation:
We know that 1760 yards are in a mile. We can convert the given info into a proportion. 440/75 = 1760/x, where x is the number of seconds it takes to run a mile. Cross-multiply to get 440x = 75*1760. Divide both sides by 440 to get x = 75*4 = 300 seconds. The problem asks for how many minutes so you have to convert 300 seconds to minutes. To do this, we have to divide 300 by 60 to get 5 minutes.
