ASU ECN 221 EXAM 1 STUDY GUIDE EXPECTED
QUESTIONS WITH VERIFIED ANSWERS
Question 1.
which of the following is a measure of dispersion?
ANSWER
interquartile range
Question 2.
the sum of deviations of the individual data elements from their mean is_____.
ANSWER
always equal to zero
Question 3.
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
Question 4.
the interquartile range is_________.
ANSWER
the difference between the third and first quartiles
Question 5.
events A and B are mutually exclusive. which of the following statements is also true?
ANSWER
P(A * B) = P(A) + P(B)
, Question 6.
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)
Question 7.
revised probabilities of events based on additional information are________.
ANSWER
posterior probabilites
Question 8.
two events with nonzero probabilities_________.
ANSWER
cannot be both mutually exclusive and independent
Question 9.
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
Question 10.
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
QUESTIONS WITH VERIFIED ANSWERS
Question 1.
which of the following is a measure of dispersion?
ANSWER
interquartile range
Question 2.
the sum of deviations of the individual data elements from their mean is_____.
ANSWER
always equal to zero
Question 3.
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
Question 4.
the interquartile range is_________.
ANSWER
the difference between the third and first quartiles
Question 5.
events A and B are mutually exclusive. which of the following statements is also true?
ANSWER
P(A * B) = P(A) + P(B)
, Question 6.
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)
Question 7.
revised probabilities of events based on additional information are________.
ANSWER
posterior probabilites
Question 8.
two events with nonzero probabilities_________.
ANSWER
cannot be both mutually exclusive and independent
Question 9.
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
Question 10.
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
