Westonci.ca connects you with experts who provide insightful answers to your questions. Join us today and start learning! Discover in-depth solutions to your questions from a wide range of experts on our user-friendly Q&A platform. Our platform provides a seamless experience for finding reliable answers from a network of experienced professionals.

One invests 100 shares of IBM stocks today. He expects that there could be five possible opening prices with the respective probabilities at 9:30 a.m. in NYSE the next day. The following table lists these possible opening prices and their respective probabilities:
Outcome 1 Outcome 2 Outcome 3 Outcome 4 Outcome 5
Possible Opening
Price of IBM, Xi $182.11 $163.88 $180.30 $216.08 $144.92
Probability, pi 13% 19% 33% 17% 18%
Let X represent the five random opening prices of IBM the next day, calculate the mean, variance, and the standard deviation of X. Make your comments on the results you obtain.

Sagot :

Answer:

[tex]E(x) = 177.130[/tex]

[tex]Var(x) = 484.551[/tex]

[tex]\sigma = 22.013[/tex]

Step-by-step explanation:

Given

The attached table

Solving (a): The mean

This is calculated as:

[tex]E(x) = \sum x * p(x)[/tex]

So, we have:

[tex]E(x) = 182.11 * 13\% + 163.88 * 19\% + 180.30 * 33\% + 216.08 * 17\% + 144.92 * 18\%[/tex]

Using a calculator, we have:

[tex]E(x) = 177.1297[/tex]

[tex]E(x) = 177.130[/tex] --- approximated

The average opening price is $177.130

Solving (b): The Variance

This is calculated as:

[tex]Var(x) = E(x^2) - (E(x))^2[/tex]

Where:

[tex]E(x^2) = \sum x^2 * p(x)[/tex]

[tex]E(x^2) = 182.11^2 * 13\% + 163.88^2 * 19\% + 180.30^2 * 33\% + 216.08^2 * 17\% + 144.92^2 * 18\%[/tex]

[tex]E(x^2) = 31859.482249[/tex]

So:

[tex]Var(x) = E(x^2) - (E(x))^2[/tex]

[tex]Var(x) = 31859.482249 - 177.1297^2[/tex]

[tex]Var(x) = 31859.482249 - 31374.9306221[/tex]

[tex]Var(x) = 484.5516269[/tex]

[tex]Var(x) = 484.551[/tex] --- approximated

Solving (c): standard deviation

The standard deviation is:

[tex]\sigma = \sqrt{Var(x)}[/tex]

[tex]\sigma = \sqrt{484.5516269}[/tex]

[tex]\sigma = 22.0125418796[/tex]

Approximate

[tex]\sigma = 22.013[/tex]

We hope this information was helpful. Feel free to return anytime for more answers to your questions and concerns. Thanks for using our service. We're always here to provide accurate and up-to-date answers to all your queries. Thank you for visiting Westonci.ca. Stay informed by coming back for more detailed answers.