# Probability and Variance

Not what you're looking for?

The cell phone industry is growing at a rapid pace. Current estimates suggest that 60% of people have cell phones. Suppose 25 people were randomly and independently sampled. Let X be the number of people in the sample having cell phones. A) The variable X follows: aa) Normal distribution. bb) Continuous distribution. cc) Binomial distribution. dd) None of the above. I think it is cc) binomial distribution, but not sure. B) Which of the following are not possible values of X? aa)0 bb)30 cc)10 dd)20. I think it is bb)30, because there is only 25 peole in the sample, but I am probably wrong. C) What is the probability that fewer than half of these samples people currently have cell phones. I believe that in order to solve this part, one must use the binomal table, but I am not sure. D)What is the variance of the number of people in the sample of 25 currently having a cell phone.

##### Purchase this Solution

##### Solution Preview

a) It follows a Binomial Distribution ( a person will either have a vell or not have ...

###### Education

- BE, Bangalore University, India
- MS, University of Wisconsin-Madison

###### Recent Feedback

- "Your explanation to the answers were very helpful."
- "What does 1 and 0 means in the repair column?"
- "Went through all of the formulas, excellent work! This really helped me!"
- "try others as well please"
- "Thank you, this helped a lot. I was not sure how to plug in those numbers to a formula. This was a great help. Now I have to figure out how to explain cost of capital is used in net present value analysis, and how cost of capital is used in net present value analysis. This stuff gets confusing."

##### Purchase this Solution

##### Free BrainMass Quizzes

##### Terms and Definitions for Statistics

This quiz covers basic terms and definitions of statistics.

##### Measures of Central Tendency

Tests knowledge of the three main measures of central tendency, including some simple calculation questions.

##### Know Your Statistical Concepts

Each question is a choice-summary multiple choice question that presents you with a statistical concept and then 4 numbered statements. You must decide which (if any) of the numbered statements is/are true as they relate to the statistical concept.

##### Measures of Central Tendency

This quiz evaluates the students understanding of the measures of central tendency seen in statistics. This quiz is specifically designed to incorporate the measures of central tendency as they relate to psychological research.