Classify the following variables as nominal, ordinal,
discrete, or continuous in questions # 1 - 5.
1. ) Number
of students absent in a statistics course. ________________________
2. ) Social security numbers.____________________________________________
3. ) The
amounts of milk that cows produce. _______________________________
4. ) Course
grades that a college professor assigns. __________________________
5. ) The
number of eggs that hens lay. ____________________________________
6. ) Construct
a Stem and Leaf plot for the following test grades data : 67, 72,
85, 75, 89, 89, 88, 90, 99, 100.
7. ) A study
was conducted to determine how people get jobs.
Construct a PIE Chart for the
following data :
Job Sources of
Survey Respondents Frequency
Help-wanted ads 56
Executive
Search Firms 44
Networking 280
Mass
Mailing 20
Use the following information to answer questions # 8 –
13.
The following values are the service times ( in seconds )
of McDonald’s drive-
through customers : 88 107 35 93 65 55 119 83 99
74 46 108
8. ) Find the
mean of the data set.
9. ) Find the
median of the data set.
10. ) Find the
range of the data set.
11. ) Find the
inter-quartile range.
12. ) Find the
60th percentile.
13. ) Draw a
boxplot. ( Make sure and clearly label the boxplot. )
14. ) Which is
relatively better : a score of 75 on a history test or a score of 27 on a
psychology test? Scores on the history test have a mean of 80
and a standard deviation of 12. Scores
on the psychology test have a mean of 30 and standard deviation of 8.
Use the following information to answer questions # 15 –
16.
The heights of men have a normal
( bell-shaped, mound shaped) distribution
with a mean of 69.0 in. and a
standard deviation of 2.8 in. ( based on data from the National Health Survey
).
15. ) What
percentage of men have heights between 60.6 in. and 77.4 in. ?
16. ) What
percentage of men have heights between 66.2 in. and 74.6 in. ?
17. ) If IQ scores have a mean of 100 and a standard
deviation of 15, what can
you conclude about the
percentage of IQ scores that are between 55 and 145 if you assume nothing about
the shape of the distribution ?
18. ) If a
person has a z-score equal to –0.86 from a set of exams that had a mean
of 74.51 and a standard
deviation of 3.5 then what was the student’s original score on the exam ?
Use the following information to answer questions # 19 –
24.
In a study on DWI and Jail the
age ( x ) of people and their blood alcohol
levels ( y ) of a person who has
been convicted and jailed for DWI are listed below. The BAC level is measured at the time of arrest. :
Age 17.2 33.5 30.7 23.1 37.2 21.0 27.6 26.3
BAC 0.19 0.20 0.26 0.16 0.24 0.20 0.18 0.23
19. ) Find the
linear correlation coefficient for Age and Blood Alcohol Level.
20. ) Interpret
(explain) the linear correlation coefficient in the previous problem.
21. ) Write the
line of best fit ( regression equation ) for age and blood alcohol
levels.
22. ) Find the estimated Blood alcohol level for
a 22.0 year old person who has been convicted and jailed for DWI.
23. ) Find the estimated Blood alcohol level for
a 19.3 year old person who has been convicted and jailed for DWI.
24. ) Find the estimated Blood alcohol level for
a 52.1 year old person who has been convicted and jailed for DWI.
25. ) For the
following frequency distribution estimate the mean of the frequency
distribution.
Height ( in.)
Frequency
55-59
172
60-64
223
65-69
135
70-74
288
75-79 197