Answer:
570 m³
Step-by-step explanation:
The volume of water is the product of flow rate of water and the time taken. We are to get the volume of water used between 6 am and 9 am, that is for 3 hours (9 - 6).
We are given the flow rate at 6 am and the flow rate at 9 am, but this flow rate changes between 6 am and 9 am. To get the estimate of the water used, Let us assume that it flows at the same flow rate as it was at 6 am throughout, hence:
![V_L= 100 m^3/h * 3h=300\ m^3](https://tex.z-dn.net/?f=V_L%3D%20100%20m%5E3%2Fh%20%2A%203h%3D300%5C%20m%5E3)
Also, let us assume that it flows at the same flow rate as it was at 9 am throughout, hence:
![V_R= 280 m^3/h * 3h=840\ m^3](https://tex.z-dn.net/?f=V_R%3D%20280%20m%5E3%2Fh%20%2A%203h%3D840%5C%20m%5E3)
To get the best estimate of the total volume, let us find the average of the two values, hence:
![Volume=\frac{V_L+V_R}{2} =\frac{300+840}{2}=570\ m^3](https://tex.z-dn.net/?f=Volume%3D%5Cfrac%7BV_L%2BV_R%7D%7B2%7D%20%3D%5Cfrac%7B300%2B840%7D%7B2%7D%3D570%5C%20m%5E3)
Answer:
x= 10/13
Step-by-step explanation:
First, we need to put the variable on one side and the constants on another side.
Also a positive and a negative equal a negative. [this is related to +(-8)]
10x+(-8)= -3x+2
+3x +3x
13x-8=2
+8 +8
13x=10
Finally you divide on both sides
13x/13=10/13
x= 10/13
I hope this is right! I tried my best
its not 100 points it 8 but i will still help you
the answer is 7.2 i believe
Answer: 1308
Step-by-step explanation:
Given : Level of confidence = 0.97
Significance level : ![\alpha=1-0.97=0.03](https://tex.z-dn.net/?f=%5Calpha%3D1-0.97%3D0.03)
Critical value : ![z_{\alpha/2}=2.17](https://tex.z-dn.net/?f=z_%7B%5Calpha%2F2%7D%3D2.17)
Margin of error : ![E=0.03](https://tex.z-dn.net/?f=E%3D0.03)
If prior proportion of population is unknown , then the formula to find the population proportion is given by :-
![n=0.25(\dfrac{z_{\alpha/2}}{E})^2](https://tex.z-dn.net/?f=n%3D0.25%28%5Cdfrac%7Bz_%7B%5Calpha%2F2%7D%7D%7BE%7D%29%5E2)
![\Rightarrow n=0.25(\dfrac{2.17}{0.03})^2=1308.02777778\approx1308](https://tex.z-dn.net/?f=%5CRightarrow%20n%3D0.25%28%5Cdfrac%7B2.17%7D%7B0.03%7D%29%5E2%3D1308.02777778%5Capprox1308)
Hence, the minimum sample size needed =1308