ECON 2013 Chapter 3 & 4 Homework 1

1. ch 3 A statistics student made the following grades on 7 tests: 76, 82, 92, 95, 79, 86, and 92.  What is the median grade?
 
 82
 
 76
 
 95
 
 94
 
 86
3 points  
QUESTION 2
1. 

ch 3  A statistics student made the following grades on 7 tests: 76, 82, 92, 95, 79, 86, and 92.   What is the mode?
 
 76
 
 82
 
 79
 
 86
 
 92
3 points  
QUESTION 3
1. ch 3  The number of standard deviations that a value (x) is above or below the mean is the
 
 absolute deviation
 
 correlation coefficient
 
 z score
 
 coefficient of variation
 
 interquartile range
2 points  
QUESTION 4
1. ch 3  The empirical rule says that approximately what percentage of the values would be within 2 standard deviations of the mean in a bell shaped (normal curve) set of data?
 
 50%
 
 97.7%
 
 95%
 
 68%
 
 100%
3 points  
QUESTION 5
1. ch 3  A commuter travels many miles to work each morning.  She has timed this trip 5 times during the last month.  The time (in minutes) required to make this trip was 38, 33, 36, 47, and 41.  What is the standard deviation for this sample data? (Hint can use Excel function for this one, or calculate it on your own)
 
 22.8
 
 11
 
 4.77
 
 5.34
 
 28.5
3 points  
QUESTION 6
1. ch 4  If X and Y are mutually exclusive events, then if X occurs _______
 
 X and Y are independent
 
 Y cannot occur
 
 X and Y are complements
 
 Y must also occur
 
 A and Y are collectively exhaustive
2 points  
QUESTION 7
1. ch 4  Consider the following sample space, S, and several events defined on it.  S = {Albert, Betty, Abel, Jack, Patty, Meagan}, and the events are:  F = {Betty, Patty, Meagan}, H = {Abel, Meagan}, and P = {Betty, Abel}.  F ∩ H  is ___________
 
 {Betty, Patty, Abel, Meagan}
 
 empty, since F and H are mutually exclusive
 
 empty, since F and H are complements
 
 empty, since F and H are independent
 
 {Meagan}
2 points  
QUESTION 8
1. ch 4  Consider the following sample space, S, and several events defined on it.  S = {Albert, Betty, Abel, Jack, Patty, Meagan}, and the events are:  F = {Betty, Patty, Meagan}, H = {Abel, Meagan}, and P = {Betty, Abel}. F ∪ H  is __________
 
 {Meagan}
 
 empty, since F and H are independent
 
 {Betty, Abel, Patty, Meagan}
 
 empty, since F and H are complements
 
 empty, since F and H are mutually exclusive
2 points  
QUESTION 9
1. ch 4  Let F be the event that a student is enrolled in a finance course, and let S be the event that a student is enrolled in a statistics course.  It is known that 40% of all students are enrolled in  a finance course and 35% of all students are enrolled in statistics.  Included in these numbers are 15% who are enrolled in both statistics and finance.  A student is randomly selected, what is the probability that the student is enrolled in either finance or statistics or both?
 
 0.60
 
 0.15
 
 0.90
 
 0.55
 
 0.75
2 points  
QUESTION 10
1. 
An automobile dealer wishes to investigate the relation between the gender of the buyer and type of vehicle purchased. Based on the following joint probability table that was developed from the dealer’s records for the previous year, P (Male) = ________
 
Type of Buyer Gender 
Vehicle Female Male Total
SUV     
Not SUV .32 .48 
Total .40   1.00

 
 
 0.48
 
 0.60
 
 0.02
 
 0.50
 
 0.20
3 points  
QUESTION 11
1. ch 4 Meagan Dubean manages a portfolio of 200 common stocks.  Her staff classified the portfolio stocks by 'industry sector' and 'investment objective.'
 
Investment Industry Sector 
Objective Electronics Airlines Healthcare Total
Growth 100 10 40 150
Income 20 20 10 50
Total 120 30 50 200
If a stock is selected randomly from Meagan's portfolio, P (Growth) = _______

 
 0.90
 
 0.50
 
 0.67
 
 0.83
 
 0.75
3 points  
QUESTION 12
1. ch 4  Assigning probability 1/52 on drawing the ace of spade in a deck of cards is an example of assigning probabilities using the ________________ method
 
 a priori probability
 
 subjective probability
 
 classical probability
 
 relative frequency
 
 a posterior probability