Broward College
Math Dept.
Statistics STA2023
Review Test # 1
1) Determine whether the given values are statistics or a parameters. Determine the population and the sample (if any):
a) In a FOX News poll conducted 5/155/172011, a sample of 910 voters were asked if they approve the job of the president Barack Obama. 55% of the respondents approve the job of the president.(taken from http://www.realclearpolitics.com/polls/) During the presidential election in 2008, 52.9% of the voters voted for Barack Obama (“http://en.wikipedia.org/wiki/United_States_presidential_election,_2008”)
b) According
to Census 2000 (“http://www.nationalatlas.gov/articles/people/a_race.html”),
281.4 million people resided in the United States at that time, 12.5
% were Latino, and 12.3
% were AfricanAmericans.
2) Engineers must consider the breadth of male heads when designing motorcycle helmets. A random sample of 30 men was selected and their head breadth is shown in the table:
3.4 
4.6 
5.2 
5.6 
5.8 
6.5 
6.6 
6.9 
7.5 
9.5 
3.4 
4.7 
5.1 
5.4 
5.8 
6.4 
6.6 
6.8 
7.0 
7.8 
4.5 
4.9 
5.0 
5.4 
5.6 
6.3 
6.5 
6.7 
6.9 
7.6 
a) Make a BoxPlot and
check for possible outliers.
b) Describe the distribution using the information obtained in a1).
3) A sample of 30 individuals was randomly selected. Their IQ is shown in the table:
87 
107 
103 
96 
98 
91 
91 
114 
87 
91 
86 
101 
106 
91 
89 
101 
100 
115 
88 
117 
112 
101 
127 
99 
102 
115 
110 
108 
93 
87 
a) Create classes. Make a frequency table showing class limits.
b) Draw a relativefrequency histogram
c) Draw a Ogive (cumulative frequency distribution
d) Describe the distribution.
4)a) Laura is playing with three dice. On her next move
she needs to throw a sum smaller than 8. What is the probability that Laura
will roll a sum smaller than 8?
b)Assume
that you want to simulate the rolling of three dice. Describe the simulation using RandomInt(). Simulate the rolling of three dice 100 times,
perform the experiment, and find the observed number of values (O)
smaller than 8. Could the values
obtained in “a” and “b” be different? Explain why? Find the residual.
5) A Gallup poll conducted in November 2002 examined how people perceive the risks associated with smoking. The following table summarizes data on smoking status and perceived risk of smoking and is consistent with summary quantities published by Gallup. Calculate the marginal distribution:
Smoking Status 
Very Harmful 
Somewhat Harmful 
Not too Harmful 
Not at All Harmful 

Current Smoker 
60 
30 
5 
1 

Former Smoker 
78 
16 
3 
2 

Never Smoked 
86 
10 
2 
1 







a) What is the probability that a randomly selected U.S. adult
is NOT a Former Smoker?
b) What is the probability that two randomly selected U.S.
adults both are Former Smoker?
c) What
is the probability that a randomly selected U.S. adult views smoking as very
harmful under the condition that the selected adult is a Current Smoker?
d) What is the probability that a randomly selected U.S. adult
views smoking as very harmful given that the selected individual never smoked?
e) What is the probability that a randomly selected U.S. adult
views smoking as very harmful OR that the selected individual is a former
smoker?
f) What is the probability that a randomly selected U.S. adult
is a current smoker AND that the selected individual considers smoking as very
harmful?
g)
Are the events Former Smoker and Very Harmful independent?