This is assignment is worth 20 points.

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Question

1 of20

Which response best summarizes the law of large numbers?

	It states the probability of matching the true mean of a distribution.
	As trials increase, the difference between the theoretical probability of an event and the relative frequency approaches zero.
	The relative frequency of an event never exactly matches the theoretical value.
	As trials increase, the difference between the theoretical probability of an event and the relative frequency approaches infinity.

Question

2 of20

Find the standard deviation of the binomial distribution for which n = 60 and p = .2.

	3.1
	.30
	9.6
	12

Question

3 of20

Decide whether the experiment is a binomial experiment. Elsa records the number of yellow marbles she gets during ten trials of randomly pulling a marble from a bag filled with marbles of various colors. The random variable represents the number of yellow marbles.

	not a binomial experiment
	binomial experiment

Question

4 of20

How many different ways could I choose three shirts to pack for a weekend trip, if I have 12 shirts to choose from? Assume the shirts are selected without replacement.

	12! / 3!
	12! / 9!
	12! / 8!4!
	12! / 9!3!

Question

5 of20

Find the mean of the binomial distribution for which n = 60 and p = .2.

	48
	30
	60
	12

Question

6 of20

If the probability of x successes in n trials is less than ___% the event can be considered unusual.

	10
	1
	4
	5

Question

7 of20

Determine whether the distribution below represents a probability distribution.

x	P(x)
1	1.2
2	1.2
3	1.4
4	1.1
5	1.1

	Is a probability distribution; the probabilities sum to 1.
	Not a probability distribution; a probability value cannot be negative.
	Not a probability distribution; a probability cannot be greater than one.

Question

8 of20

Which of the following is not a condition of the binomial distribution?

	only 2 possible outcomes
	have a constant probability of success
	Must have at least 3 trials
	trials must be independent

Question

9 of20

State whether the variable is discrete or continuous. The cost of a statistics textbook

	discrete
	continuous

Question

10 of20

A test consists of 10 true or false questions. To pass the test a student must answer at least eight questions correctly. If the student guesses on each question, what is the probability that the student will pass the test?

	0.20
	0.055
	0.08
	0.8

Question

11 of20

Determine the probability distribution's missing value.

The probability that a tutor will see 0, 1, 2, 3, or 4 students

x	0	1	2	3	4
P(x)	.57	.07	.16	.02	?

	.36
	-.82
	.18
	.82

Question

12 of20

Decide whether the experiment is a binomial experiment. Testing a pain reliever using 840 people to determine if it is effective. The random variable represents the number of people who find the pain reliever to be effective.

	binomial experiment
	not a binomial experiment

Question

13 of20

Remember that random variables can be either discrete or continuous. Which of the following are continuous random variables? (select all that apply)

	The distance a person has walked in a day
	How many glasses of water a person consumes in a day
	The number of steps a person has walked in a day
	The time it takes someone to tie their shoes

Question

14 of20

Determine whether the distribution represents a probability distribution.

x	P(x)
1	.49
2	.05
3	.32
4	.07
5	.07

	Is a probability distribution; the probabilities sum to 1.
	Not a probability distribution; the probabilities do not sum to 1.
	Not a probability distribution; a probability value cannot be negative.
	Not a probability distribution; a probability cannot be greater than one.

Question

15 of20

Which of the following variable(s) would be considered a discrete random variable? (Select all that apply)

	The number of students who bring their lunch to school instead of eating what the cafeteria serves.
	The number races a race car driver competes in during a given year.
	The average speed of a race car during a given race.
	The time it takes a student to finish his/her lunch.

Question

16 of20

The expected value a discrete probability is determined as

	x P(x)
	(x - )2
	(x - )2P(x)
	x / N

Question

17 of20

If the expected value of an extended warranty sold by an electronics store is $21, what does that mean?

	by the customer.
	The store makes $21 in revenue each time they sell this warranty.
	If store sells this same warranty many, many times, they will make (on average) $21 in revenue for each warranty sold.
	If a customer purchases this warranty and their item breaks, the store will lose $21 when they replace the item.

Question

18 of20

The random variable x represents the number of boys in a family of three children. Assuming that boys and girls are equally likely, find the mean and standard deviation for the random variable x.

	mean: 2.25; standard deviation: 0.76
	mean: 1.50; standard deviation: 0.76
	mean: 2.25; standard deviation: 0.87
	mean: 1.50; standard deviation: 0.87

Question

19 of20

State whether the variable is discrete or continuous. The speed of a car on a Phoenix freeway during rush hour traffic

	discrete
	continuous

Question

20 of20

Interpret P(x) = .037

	It is just a formula.
	x = .037
	P = .037 / x
	The probability of obtaining the outcome denoted by x is 3.7%