5_1
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Determine whether the situation proposed is a relative frequency definition or a subjective definition.
1) A travel agent calculates the probability that an airline will be on time for a given flight by looking
at their flight records for that city pair over the past two years.
A) Relative frequency definition
B) Subjective definition
1)
2) Potential investors for a new housing community would like an estimate for the probability that
80% of the lots will be sold by the end of the first six months of sales.
A) Subjective definition
B) Relative frequency definition
2)
3) If both parents are carriers for Tay-Sachs, the probability that their child will have Tay-Sachs is
25%.
A) Relative frequency definition
B) Subjective definition
3)
Provide an appropriate response.
4) You have flipped a coin 5 times in a row and gotten heads on each flip. What is your next flip most
likely to be and why?
A) Either heads or tails, the probability of heads (tails) remains constant from one flip to the next
B) Tails since the probability of 5 tails in 10 throws is 50% so the next five throws are likely to be
tails
C) Tails because the probability of six heads in a row is very small
D) Heads because the probability of heads is 1 based on the first 5 throws
E) Heads because the coin is obviously not balanced
4)
5) Both parents are carriers for an inheritable trait so that the probability their child possesses the trait
is 25%. Given that the couple has 4 children, which of the following is true?
A) Exactly one of the children must possess the trait
B) It is impossible that all four children possess the trait
C) At least two of the children must possess the trait
D) It is possible that none of the four children possess the trait
5)
6) You flip a coin x number of times and calculate the probability of heads as (number of heads)/x.
What happens to this probability as x gets larger?
A) It stays the same, 0.50
B) It gets closer and closer to 0.50
C) It gets smaller
D) It gets larger
6)
7) You play a game where you are to guess under which of 4 cups a coin has been placed. How many
times would you expect to guess correctly in 20 plays of the game? Note that the coin is moved
after each play.
A) 10
B) 4
C) 1
D) 5
7)
8) You play a game where you are to guess under which of 4 cups a coin has been placed. Given that
you guess incorrectly the first 3 plays, what is the most likely outcome of the fourth play? Note that
the coin is moved after each play.
A) You guess incorrectly since the probability of an incorrect guess is 0.75 which is higher than
the probability of a correct guess (0.25)
B) You guess correctly since the probability of a correct guess is 1 in 4
C) You guess correctly because out of four plays, you must guess correctly at least once
D) You guess incorrectly because the probability of you guessing incorrectly is 1 (3/3)
8)
1
Answer true or false.
9) If you roll a die 50 times, you are guaranteed to see each of the six faces at least once.
A) True
B) False
10) Two trials are independent if they have no outcomes in common.
A) True
B) False
2
9)
10)
Answer Key
Testname: 5_1
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
A
A
A
A
D
B
D
A
B
B
3