ASU ECN 221 EXAM 1 STUDY GUIDE | VERIFIED STUDY |
QUESTIONS AND ANSWERS | 2026 UPDATES |
GUARANTEED PASS
which of the following is a measure of dispersion? - ANSWER- interquartile range
the sum of deviations of the individual data elements from their mean is_____. - ANSWER-
always equal to zero
the value of the sum of the squared deviations form the mean, i.e., summation(x-xbar)^2 must
always be______. - ANSWER- at least zero
the interquartile range is_________. - ANSWER- the difference between the third and first
quartiles
events A and B are mutually exclusive. which of the following statements is also true? -
ANSWER- P(A ∪ B) = P(A) + P(B)
if A and B are independent events with P(A)=0.301 and P(B)=0.253, then P(A ∩ B)=_________ -
ANSWER- 0.07615 (multiply the two numbers)
revised probabilities of events based on additional information are________. - ANSWER-
posterior probabilites
two events with nonzero probabilities_________. - ANSWER- cannot be both mutually
exclusive and independent
Five Cs Bank issues credit cards to its customers. In the past 3.4% of the out-of-state
nonfraudulent credit card transactions were made at gasoline stations and 9.2% of the out-of-
state fraudulent credit card transactions were made at gasoline stations. Based on historical
transactions 97.7% of out-of-state credit card transactions are legitimate while the rest of its
out-of-state credit card transactions are fraudulent. An out-of-state credit card transaction took
place at a gasoline station, what is the probability the transaction is fraudulent? - ANSWER-
0.059886
What is the probability that a customer is in the 18-30 age group?
Product Preference age 18-30 age 31-45 age 46+
, Strawberry 33 36 32
Blueberry 14 23 27 - ANSWER- 0.284848
what is the probability that a customer is in tempe or prefers chocolate or both?
Product Preference Flagstaff Tempe Tucson
Vanilla 43 71 31
Chocolate 35 61 32 - ANSWER- 0.728938
what is the probability that a customer is in the 46+ age group?Product Preference age 18-30
age 31-45 age 46+
Strawberry 53 27 33
Blueberry 22 25 27 - ANSWER- 0.320856
The random variable x is the number of occurrences of an event over an interval of 10 minutes.
It can be assumed the probability of an occurrence is the same in any two time periods of an
equal length. It is known that the mean number of occurrences in 10 minutes is 5.3.
Refer to exhibit 5-11. the probability there are 8 more occurrences in 10 minutes is_________. -
ANSWER- 0.0771
What is P(YES warranty | PAID CASH)?
Warranty purchase PAID CASH STORE CREDIT ACCT CREDIT CARD
YES 2 12 53
NO 9 20 71 - ANSWER- 0.181818
the student body of a large university consists of 61% female students. a random sample of 8
students is selected. what is the random variable in this experiment? - ANSWER- the
number of female students out of 8
the probability of no breakdowns in a month is____________.
# of breakdowns probability
0 .12
QUESTIONS AND ANSWERS | 2026 UPDATES |
GUARANTEED PASS
which of the following is a measure of dispersion? - ANSWER- interquartile range
the sum of deviations of the individual data elements from their mean is_____. - ANSWER-
always equal to zero
the value of the sum of the squared deviations form the mean, i.e., summation(x-xbar)^2 must
always be______. - ANSWER- at least zero
the interquartile range is_________. - ANSWER- the difference between the third and first
quartiles
events A and B are mutually exclusive. which of the following statements is also true? -
ANSWER- P(A ∪ B) = P(A) + P(B)
if A and B are independent events with P(A)=0.301 and P(B)=0.253, then P(A ∩ B)=_________ -
ANSWER- 0.07615 (multiply the two numbers)
revised probabilities of events based on additional information are________. - ANSWER-
posterior probabilites
two events with nonzero probabilities_________. - ANSWER- cannot be both mutually
exclusive and independent
Five Cs Bank issues credit cards to its customers. In the past 3.4% of the out-of-state
nonfraudulent credit card transactions were made at gasoline stations and 9.2% of the out-of-
state fraudulent credit card transactions were made at gasoline stations. Based on historical
transactions 97.7% of out-of-state credit card transactions are legitimate while the rest of its
out-of-state credit card transactions are fraudulent. An out-of-state credit card transaction took
place at a gasoline station, what is the probability the transaction is fraudulent? - ANSWER-
0.059886
What is the probability that a customer is in the 18-30 age group?
Product Preference age 18-30 age 31-45 age 46+
, Strawberry 33 36 32
Blueberry 14 23 27 - ANSWER- 0.284848
what is the probability that a customer is in tempe or prefers chocolate or both?
Product Preference Flagstaff Tempe Tucson
Vanilla 43 71 31
Chocolate 35 61 32 - ANSWER- 0.728938
what is the probability that a customer is in the 46+ age group?Product Preference age 18-30
age 31-45 age 46+
Strawberry 53 27 33
Blueberry 22 25 27 - ANSWER- 0.320856
The random variable x is the number of occurrences of an event over an interval of 10 minutes.
It can be assumed the probability of an occurrence is the same in any two time periods of an
equal length. It is known that the mean number of occurrences in 10 minutes is 5.3.
Refer to exhibit 5-11. the probability there are 8 more occurrences in 10 minutes is_________. -
ANSWER- 0.0771
What is P(YES warranty | PAID CASH)?
Warranty purchase PAID CASH STORE CREDIT ACCT CREDIT CARD
YES 2 12 53
NO 9 20 71 - ANSWER- 0.181818
the student body of a large university consists of 61% female students. a random sample of 8
students is selected. what is the random variable in this experiment? - ANSWER- the
number of female students out of 8
the probability of no breakdowns in a month is____________.
# of breakdowns probability
0 .12
