Answer:
d definetly d
Step-by-step explanation:
Answer: 271
Step-by-step explanation:
The formula we use to find the sample size is given by :-
![n=p(1-p)(\dfrac{z_{\alpha/2}}{E})^2](https://tex.z-dn.net/?f=n%3Dp%281-p%29%28%5Cdfrac%7Bz_%7B%5Calpha%2F2%7D%7D%7BE%7D%29%5E2)
, where
is the two-tailed z-value for significance level of ![(\alpha)](https://tex.z-dn.net/?f=%28%5Calpha%29)
p = prior estimation of the proportion
E = Margin of error.
If prior estimation of the proportion is unknown, then we take p= 0.5 , the formula becomes
![n=0.5(1-0.5)(\dfrac{z_{\alpha/2}}{E})^2](https://tex.z-dn.net/?f=n%3D0.5%281-0.5%29%28%5Cdfrac%7Bz_%7B%5Calpha%2F2%7D%7D%7BE%7D%29%5E2)
![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)
Given : Margin of error : E= 0.05
Confidence level = 90%
Significance level ![\alpha=1-0.90=0.10](https://tex.z-dn.net/?f=%5Calpha%3D1-0.90%3D0.10)
Using z-value table , Two-tailed z-value for significance level of ![0.10](https://tex.z-dn.net/?f=0.10)
![z_{\alpha/2}=1.645](https://tex.z-dn.net/?f=z_%7B%5Calpha%2F2%7D%3D1.645)
Then, the required sample size would be :
![n=0.25(\dfrac{1.645}{0.05})^2](https://tex.z-dn.net/?f=n%3D0.25%28%5Cdfrac%7B1.645%7D%7B0.05%7D%29%5E2)
Simplify,
![n=270.6025\approx271](https://tex.z-dn.net/?f=n%3D270.6025%5Capprox271)
Hence, the required minimum sample size =271
Ratio of girls : boys = 5 : 4
<u>Find total parts:</u>
Total parts = 5 + 4 = 9
<u>Find 1 part:</u>
9 parts = 36
1 part = 36 ÷ 9 = 4
<u>Find 5 parts (Girls):</u>
Girls = 5 parts = 4 x 5 = 20
Answer: There are 20 girls.
Answer:
65.9 so it rounds to 66cm
Answer: g=2
Step-by-step explanation:5.5g+3=2.5g+9
We move all terms to the left:
5.5g+3-(2.5g+9)=0
We get rid of parentheses
5.5g-2.5g-9+3=0
We add all the numbers together, and all the variables
3g-6=0
We move all terms containing g to the left, all other terms to the right
3g=6
g=6/3
g=2