A scientist claims that 9% of viruses are airborne.


If the scientist is accurate, what is the probability that the proportion of airborne viruses in a sample of 596 viruses would differ from the population proportion by greater than 3%?

Respuesta :

Answer:

The probability that the sample proportion of airborne viruses in differ from the population proportion by greater than 3% is 0.006.

Step-by-step explanation:

According to the Central limit theorem, if from an unknown population large samples of sizes n > 30, are selected and the sample proportion for each sample is computed then the sampling distribution of sample proportion follows a Normal distribution.

The mean of this sampling distribution of sample proportion is:

[tex]\mu_{\hat p}=p[/tex]  

The standard deviation of this sampling distribution of sample proportion is:

[tex]\sigma_{\hat p}=\sqrt{\frac{p(1-p)}{n}}[/tex]

The information provided is:

n = 596

p = 0.09

As the sample size is quite large, i.e. n = 596 > 30, the central limit theorem can be used to approximate the sampling distribution of sample proportion by a Normal distribution.

The mean and standard deviation are:

[tex]\mu_{\hat p}=p=0.09\\\\\sigma_{\hat p}=\sqrt{\frac{p(1-p)}{n}}=\sqrt{\frac{0.09(1-0.09)}{596}}=0.012[/tex]

Compute the probability that the sample proportion of airborne viruses in differ from the population proportion by greater than 3% as follows:

[tex]P(\hat p-p>0.03)=P(\hat p>0.12)[/tex]

                         [tex]=P(\frac{\hat p-\mu_{\hat p}}{\sigma_{\hat p}}>\frac{0.12-0.09}{0.012})\\\\=P(Z>2.5)\\\\=1-P(Z<2.5)\\\\=1-0.99379\\\\=0.00621\\\\\approx 0.006[/tex]

Thus, the probability that the sample proportion of airborne viruses in differ from the population proportion by greater than 3% is 0.006.