How do I know this? well, those red arrows on the line show that those 2 sides (ED) and (AB) are congruent which means they are equal. therefore if they are equal and we know ED is 2, then we know AB is also 2. Hope this helped :)

7 0

3 years ago

What sample size is needed to give a margin of error within plus-or-minus 5% in estimating a population proportion with 90% conf

VARVARA [1.3K]

Answer: 271.

Step-by-step explanation:

When the prior population proportion of success is not available, then the formula to find the sample size is given by :-

$n=00.25(\dfrac{z_{\alpha/2}}{E})^2$

Given : Significance level : $\alpha: 1-0.90=0.1$

By using the standard normal distribution table ,

Critical value : $z_{\alpha/2}=1.645$

Margin of error : $E=0.05$

Then , the required minimum sample size will be :-

$n=0.25(\dfrac{(1.645)}{0.05})^2=270.6025\approx271$

Hence, the required minimum sample size is 271.

4 0

3 years ago