Respuesta :
Recall that margin of error is given by:
[tex]M=z_{\alpha/2}\sqrt{ \frac{p(1-p)}{n}} \\ \\ \Rightarrow\frac{M^2}{\left(z_{\alpha/2}\right)^2}= \frac{p(1-p)}{n} \\ \\ \Rightarrow n= \frac{\left(z_{\alpha/2}\right)^2p(1-p)}{M^2} [/tex]
Given that you want to be 95% confident that the sample percentage is within 2.5 percentage points of the true population percentage.
This means that [tex]z_{\alpha/2}=1.96[/tex] and M = 2.5% = 0.025.
Part A:
When nothing is known about the percentage of persengers who prefer aisle seat, we make use of p = 50% = 0.5.
Thus,
[tex]n=\frac{1.96^2\times0.5\times0.5}{(0.025)^2}= \frac{0.9604}{0.000625} =1,537[/tex]
Therefore, 1,537 randomly selected air passengers must be surveyed to be 95% confident that the sample percentage is within 2.5 percentage points of the true population percentage.
Part B:
Given that recent surveys surgest that about 38% of all air passengers prefer an aisle seat, thus p = 38% = 0.38
Thus,
[tex]n=\frac{1.96^2\times0.38\times0.62}{(0.025)^2}= \frac{0.9051}{0.000625} =1,449[/tex]
Therefore, 1,449 randomly selected air passengers must be surveyed to be 95% confident that the sample percentage is within 2.5 percentage points of the true population percentage.
[tex]M=z_{\alpha/2}\sqrt{ \frac{p(1-p)}{n}} \\ \\ \Rightarrow\frac{M^2}{\left(z_{\alpha/2}\right)^2}= \frac{p(1-p)}{n} \\ \\ \Rightarrow n= \frac{\left(z_{\alpha/2}\right)^2p(1-p)}{M^2} [/tex]
Given that you want to be 95% confident that the sample percentage is within 2.5 percentage points of the true population percentage.
This means that [tex]z_{\alpha/2}=1.96[/tex] and M = 2.5% = 0.025.
Part A:
When nothing is known about the percentage of persengers who prefer aisle seat, we make use of p = 50% = 0.5.
Thus,
[tex]n=\frac{1.96^2\times0.5\times0.5}{(0.025)^2}= \frac{0.9604}{0.000625} =1,537[/tex]
Therefore, 1,537 randomly selected air passengers must be surveyed to be 95% confident that the sample percentage is within 2.5 percentage points of the true population percentage.
Part B:
Given that recent surveys surgest that about 38% of all air passengers prefer an aisle seat, thus p = 38% = 0.38
Thus,
[tex]n=\frac{1.96^2\times0.38\times0.62}{(0.025)^2}= \frac{0.9051}{0.000625} =1,449[/tex]
Therefore, 1,449 randomly selected air passengers must be surveyed to be 95% confident that the sample percentage is within 2.5 percentage points of the true population percentage.
- 1,537 randomly selected air passengers must be surveyed to be 95 percent confident within 2.5 percentage points of the sample percentage by using p=50 percent.
- 1,449 randomly selected air passengers must be surveyed to be 95 percent confident within 2.5 percentage points of the sample percentage by using p=38 percent.
Step by Step Explanation:
You want 95% confidence within 2.5% points of the actual population.
The margin of error can be formulated as given below:
[tex]\begin{aligned}M&=Z_{\alpha/2}} \times \sqrt{\dfrac{p(p-1)}{n}}\\\dfrac{M^2}{[Z_{\alpha/2}]^2}}&=\dfrac{p(p-1)}{n}\\n&=\dfrac{[Z_{\alpha/2}]^2 \times p(p-1)}{M^2} \end{aligned}[/tex]
Part-(A)
Using p=50%
Substitute the values in the above formula and solve for the n.
Thus,
n=1537.
Part-(B)
Substitute the values in the above formula and solve for the n.
Thus,
n=1449.
To know more, please refer to the link:
https://brainly.com/question/19435930?referrer=searchResults