Cilantro tastes like soap to some people. This soap taste is inherited through the olfactory receptor gene OR6A2. About 14% of the population has this gene.

You want to estimate the proportion of Americans who have this gene. How large a sample must you test, with a 3% margin of error and 95% confidence, to estimate the proportion of people who carry the OR6A2 gene?

Respuesta :

Answer:

You must test a sample size of at least 514 Americans.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence interval [tex]1-\alpha[/tex], we have the following confidence interval of proportions.

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which

z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex] is the margin of error.

95% confidence interval

So [tex]\alpha = 0.05[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]z = 1.96[/tex].

We have that:

[tex]M = 0.03, \pi = 0.14[/tex]

So

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]0.03 = 1.96\sqrt{\frac{0.14*0.86}{n}}[/tex]

[tex]0.03\sqrt{n} = 0.68[/tex]

[tex]\sqrt{n} = 22.67[/tex]

[tex]n = 513.92[/tex]

You must test a sample size of at least 514 Americans.

Answer:

Sample size of at least 514 Americans is required.

Step-by-step explanation:

We are given that the soap taste is inherited through the olfactory receptor gene OR6A2. About 14% of the population has this gene.

Let p = % of population having this gene = 0.14

Also, Margin of error = 3%

        Confidence level = 95%

Margin of error formula = [tex]Z_\frac{\alpha}{2} * \frac{\sigma}{\sqrt{n} }[/tex]

where, [tex]Z_\frac{\alpha}{2}[/tex] = At 5% level of significance z score has value of 1.96

             [tex]\sigma[/tex] = [tex]\sqrt{p(1-p)}[/tex] = [tex]\sqrt{0.14 * 0.86}[/tex] = 0.347

So, Margin of error = [tex]1.96* \frac{\sqrt{0.14*0.86} }{\sqrt{n} }[/tex]

            [tex]\sqrt{n}[/tex] = [tex]\frac{1.96*0.347}{0.03}[/tex]

             n = [tex]22.671^{2}[/tex] = 513.95 ≈ 514

Therefore, sample must be of 514 Americans .