Statistics
oktobeme_29
ch5quiz_new1.docxMATH 153/Statistics/CCBC Chapter 5 Quiz NAME_______________________
SCORE __________/26 pts
Directions: As always, show all work for full credit. Place answers in boxes or blanks where provided.
1. You take a quiz that has five true/false questions. Let X be the number of questions that a student answers correctly. List all values that the random variable can assume: _____________________________ ( 2 pts)
2. What are the FOUR requirements of a binomial distribution? (2 pts)
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
3. You are at a county fair and you play a game in which there are pink ducks, blue ducks and yellow ducks. If you catch a pink duck, you win $5.00, if you catch a blue duck, you win $1.00, and if you catch a yellow duck, you win nothing. The probability of catching a pink duck is 5% and the probability of catching a blue duck is 10%. Fill in the chart for the probability distribution (2 pts), calculate the expected value (3 pts) and explain what it means (2 pts)
|
|
X |
P(x) |
|
|
Pink |
|
|
|
|
Blue |
|
|
|
|
Yellow |
|
|
|
Expected Value _________________ (3 pts)
Explain in every-day English what this answer means in the context of the problem (2 pts):
______/11 pts
4. Based on a Comcast survey, there is an 80% chance that a randomly selected adult will watch prime-time TV live as opposed to through another source (internet, DVR, etc.). Assume that seven adults are randomly selected and find the probabilities indicated below.
a. Find the probability that exactly 6 of the selected adults watch prime-time TV live (4 pts)
b. Find the probability that more than five of the selected adults watches prime-time TV live (5 pts)
c. What is the mean? (2 pts)
d. What is the standard deviation? (2 pts)
e. Is two an unusually low number for those who watch prime-time TV live? Use math to justify your work and explain. (2 pts)
______/15 pts
2
