Answer:
7z
Step-by-step explanation:
Answer:
7z
Step-by-step explanation:
4z-(-3z).
Two negatives equal a positive only <u>when they are right next to each other.</u>
4z+3z=7z. Hope this helps :D
Answer:
B and D
Step-by-step explanation:
Take a look at all the options x=4, 3, 1, 2 > 0
So, we just care about the domain where x>0, which is
.
Then plug in x we will have the right answer.
Answer: a) 683 b) 1067
Step-by-step explanation:
The confidence interval for population proportion is given by :-
![p\pm z_{\alpha/2}\sqrt{\dfrac{p(1-p)}{n}}](https://tex.z-dn.net/?f=p%5Cpm%20z_%7B%5Calpha%2F2%7D%5Csqrt%7B%5Cdfrac%7Bp%281-p%29%7D%7Bn%7D%7D)
a) Given : Significance level :![\alpha=1-0.95=0.05](https://tex.z-dn.net/?f=%5Calpha%3D1-0.95%3D0.05)
Critical value : ![z_{\alpha/2}}=\pm1.96](https://tex.z-dn.net/?f=z_%7B%5Calpha%2F2%7D%7D%3D%5Cpm1.96)
Margin of error : ![E=0.03](https://tex.z-dn.net/?f=E%3D0.03)
Formula to calculate the sample size needed for interval estimate of population proportion :-
![n=p(1-p)(\dfrac{z_{\alpha/2}}{E})^2\\\\=0.2(0.8)(\dfrac{1.96}{0.03})^2=682.951111111\approx683](https://tex.z-dn.net/?f=n%3Dp%281-p%29%28%5Cdfrac%7Bz_%7B%5Calpha%2F2%7D%7D%7BE%7D%29%5E2%5C%5C%5C%5C%3D0.2%280.8%29%28%5Cdfrac%7B1.96%7D%7B0.03%7D%29%5E2%3D682.951111111%5Capprox683)
Hence, the required sample size would be 683 .
b) If no estimate of the sample proportion is available then the formula to calculate sample size will be :-
![n=0.25(\dfrac{z_{\alpha/2}}{E})^2\\\\=0.25(\dfrac{1.96}{0.03})^2=1067.11111111\approx1067](https://tex.z-dn.net/?f=n%3D0.25%28%5Cdfrac%7Bz_%7B%5Calpha%2F2%7D%7D%7BE%7D%29%5E2%5C%5C%5C%5C%3D0.25%28%5Cdfrac%7B1.96%7D%7B0.03%7D%29%5E2%3D1067.11111111%5Capprox1067)
Hence, the required sample size would be 1067 .
Take 156, divide by 13 and the multiply by 12. It is 144