Find expert answers and community insights on IDNLearn.com. Our platform is designed to provide accurate and comprehensive answers to any questions you may have.
Sagot :
Given:
Sample size = 100
p = 30% = 0.30
p' = 25% = 0.25
Let's find the probability that a sample proportion will over- or under-estimate the parameter by more than 5%.
Here, the error is:
Errror = |p' - p| = |0.25 - 0.30| = |-0.05| = 0.05
This error is not surprising.
Now, apply the formula:
[tex]\begin{gathered} \sigma p^{\prime}=\sqrt{\frac{p(1-p)}{n}} \\ \\ \sigma p^{\prime}=\sqrt{\frac{0.3(1-0.3)}{100}} \\ \\ \sigma p^{\prime}=\sqrt{\frac{0.3(0.7)}{100}}=\sqrt{\frac{0.21}{100}}=\sqrt{0.0021}=0.0458 \end{gathered}[/tex]Now, to find the probability that a sample proportion will be over or underestimate more than 5% will be:
[tex]\begin{gathered} p(p^{\prime}<0.3-0.05)+p(p^{\prime}>0.3+0.05) \\ \\ p(p^{\prime}<0.25)+p(p^{\prime}>0.35) \\ \\ z=\frac{p^{\prime}-\mu p^{\prime}}{\sigma p} \\ \\ Where:\mu p^{\prime}=0.3 \\ \end{gathered}[/tex]Hence, we have:
[tex]\begin{gathered} p(z<\frac{0.25-0.3}{0.0458})+p(z>\frac{0.35-0.3}{0.0458}) \\ \\ p(z<\frac{-0.05}{0.0458})+p(z>\frac{0.05}{0.0458}) \\ \\ p(z<-1.09)+p(z>1.09) \end{gathered}[/tex]Using the standard normal distribution table, we have:
NORMSDIST(-1.09) =0.1379
NORMSDIST(1.09) = 0.8621
Hence, we have:
p(z<-1.09) = 0.1379
p(z>1.09) = 1 - 0.8621 = 0.1379
p(z<-1.09) + p(z>1.09) = 0.1379 + 0.1379 = 0.2758
Therefore, the probability is 0.2758.
ANSWER:
0.2758
Thank you for being part of this discussion. Keep exploring, asking questions, and sharing your insights with the community. Together, we can find the best solutions. IDNLearn.com provides the best answers to your questions. Thank you for visiting, and come back soon for more helpful information.