MCQ Unsolved : Statistics & Probability

1. A survey was developed to estimate the average number of hours per week that adults spend exercising. Every third person entering a large fitness complex was surveyed, with a total of 2,500 people being surveyed.  The data showed that the mean number of hours spent exercising was 3.2 hours per week. Which characteristic of the survey could create a bias in the results?

[1]  the size of the sample

[2]  the method of analyzing the data

[3]  the method of choosing the people who were surveyed

[4]  the size of the population

2.  The data, shown at the right, was collected regarding the class size of the Advanced Placement courses offered at a local high school.  Which statement about the range of this sample is true? 

[1]  range < standard deviation

[2]  range = mean

[3]  range > mean

[4]  range < mean    

3.  Jason and Eric discovered that the means of their grades for the first marking period in their math class were identical.  They also noticed that the standard deviation of Jason's grades is 20.7, while the standard deviation of Eric's grades is 2.7.  Which statement must be true?      
[1] In general, Eric's grades were lower than Jason's grades.
[2] Eric's grades are more consistent than Jason's grades

[3] Eric had more failing grades during the marking period than Jason had.

[4] The median for Eric's grades is lower than the median for Jason's grades.

4.  The population growth in Youngstown is shown in the accompanying graph.  If the same pattern of population growth continues, what will the population of Youngstown be in the year 2020?

[1]  64,000 

[2]  40,000 

[3]  32,000 

[4]  20,000     

5.  A pair of dice are rolled. What is the probability of rolling 10 or less?
[1]  3/36             
[3]   10/36          
[2]  33/36            
[4]   6/36

6. On a standardized test, Alisha received a score of 85, which was exactly 2 standard deviations above the mean.  If the standard deviation for the test is 4, what is the mean for this test?      
[1]  93                      
[2]  87                    
[3]  83                
[4]  77

7.  In the accompanying diagram, about 68% of the scores fall within the shaded area, which is symmetric about the mean .  The distribution is normal and the scores in the shaded area range from 50 to 80.  What is the standard deviation of the scores in this distribution?  

[1]  7.5          
[2]  15          
[3]  30        
[4]  65    

8. The average score for a Biology test is 77 and the standard deviation is 8.  Which percent best represents the probability that any one student scored between 61 and 93 on the test? [1]  99.5%                  
[2]  95%                
[3]  68%                  
[4]  34%

9. If  nCr  represents the number of combinations of n items taken r at a time, what is the value of      
[1]  24                          
[2]   14                
[3]  6                            
[4]   4

10.  A basketball squad has ten players.  Which expression represents the number of five-player teams that can be made if Tucker, the team captain, must be on every team?      
[1]  10C5                      
[2]  9C4                    
[3]  9P4                    
[4]  10P5

11.  A committee of five members is to be randomly selected from a group of nine freshman and seven sophomores.  Which expression represents the number of different committees of three freshman and two sophomores that can be chosen?      
[1]   9P3 • 7P2              
[2]  9C3 + 7C2            
[3]  16C3 • 16C2              
[4]  9C3 • 7C2