STAT 200 PSU Quiz 4 STAT 200 PSU Quiz 4

1.

Suppose that a student needs to buy 10 books for her history course. The number of books that she will be able to find used is a binomial random variable X with n = 10 and p = 0.30. In other words, the probability that she will find any given book used is 0.30, and is independent from one book to the next. What is the probability that she will find no more than 2 used books?

[removed]A) 0.382 
[removed]B) 0.256 
[removed]C) 0.618 
[removed]D) 0.744 

Feedback: Open Minitab and go to Calc > Probability Distributions > Binomial. Since we wantno more than 2 choose Cumulative Probability and enter 10 for number of trials, 0.3 for Probability of Success, click Input Constant and enter 2. This results in probability of P(X ≤ 2) = 0.382.

2.

Use software to answer the following: You just found out that you have been kicked out of your apartment (through no fault of your own!) and need to find a new place to live. Suppose monthly rent for an individual is a normally distributed random variable with a mean of 334 dollars and a standard deviation of 22 dollars. What is the probability that you will find an apartment that costsless than 300 dollars per month.

[removed]A) 0.061118 
[removed]B) 0.766471 
[removed]C) 0.998650 
[removed]D) 0.003661 
[removed]E) 0.938882 
[removed]F) 0.233529 
[removed]G) 0.001350 
[removed]H) 0.996339 

Feedback: Go to Calc > Probability Distributions > Normal. Select "Cumulative Probability" and enter 334 for the Mean and 22 for the Standard Deviation. Select "Input Constant" and enter 300. Click OK and the answer is 0.0611182