Download MTH 591

MTH 508
Test
Name ________________________
DIRECTIONS: Calculators, books, and notes are legal. Other people are not legal. If you would
like, write any assumptions you use next to your answer. Answer each question based on the
given information. There are 50 problems.
1-10. True or False
1. Hair color would be an example of quantitative data. True or False
2. Heights of 5th graders would be an example of qualitative data. True or False
3. A parameter is the measure of some characteristic of a population. True or False
4. The “thickness of a piece of paper” used in printing of a text book is an example of a qualitative
variable. True or False
5. Measures of central tendency are numerical values that locate, in some sense, the center of a set of
data. True or False
6. The standard deviation is the positive square root of the variance. True or False
7. The median, the midrange, and the midquartile are always the same value, since each is a middle
value. True or False
8. If the value of the coefficient of linear correlation, r, is near –1 for two variables, then there is little
if any correlation between the two variables. True or False
9. If the data points form a straight horizontal or vertical line, there is strong correlation.
True or False
10. The closer the absolute value of r is to one, the better will be the predictions made using the
equation of the line of best fit, provided the prediction is made for x values between the smallest
value of x and the largest value of x in the observed data. True or False
11 - 20. Multiple Choice If the correct answer is not present, feel free to write it in as E.
11. Which of the following best describes the data: grade point averages for seniors?
A. Attribute data
B. Quantitative data
C. Qualitative data
D. Categorical data
12. Which of the following best describes the data: classifications of unlikely, likely, or very likely to
describe possible buying of a product?
A. Attribute data
B. Numerical data
C. Quantitative data
D. Bivariate data
13. Which of the following data types would be considered attribute data?
A. Hair color
B. Ages of college freshmen
C. 18 hole score of golfers
D. Shoe size of 3rd grade students
14. Suppose you are interested in determining the mean age of all students attending community
colleges in the state of Texas. Which of the following best describes this problem?
A. This is a problem in probability.
B. This is a problem in statistics.
C. Neither A nor B
D. Both A and B
15. Which of the following types of graphs would not be good for qualitative data?
A. Box-and-whisker display
B. Circle graph
C. Bar graph
D. None of the above
16. For a normal distribution, a value that is two standard deviations below the mean would be closer
to which of the following?
A. Third percentile
B. First quartile
C. Fortieth percentile
D. Median
17. Which of the following is a correct statement?
A. The mean is a measure of the deviation in a data set.
B. The standard deviation is a measure of dispersion.
C. The range is a measure of central tendency.
D. The median is a measure of dispersion.
18. The difference between the largest and smallest values in an ordered array is called the:
A. Standard deviation
B. Variance
C. Interquartile range
D. Range
19. which of the following situations is it appropriate to use a scatter diagram?
A. Presenting two qualitative variables
B. Presenting one qualitative and one quantitative variable
C. Presenting two quantitative variables
D. All of the above
20. Select the most likely answer for the coefficient of linear correlation for the two variables
described below
x = the number of hours spent studying for a test, and
y = the number of points earned on the test
A. r = 1.20
B. r = 0.70
C. r = -0.85
D. r = 0.05
21 – 28. The test scores of a 9th grade algebra test were recently collected for 20 students.
The data is as follows:
62, 64, 68, 70, 73, 76, 77, 78, 79, 81, 82, 85, 85, 85, 88, 89, 91, 94, 96, 97
Find the following:
21. Mean
22. Quartile 1
23. Quartile 2 (median)
24. Quartile 3
25. Midquartile
26. P68
27. Range
28. Mode.
29. According to the empirical rule, at least what percent of a set of data will lie within two standard
deviations from the mean?
____________________
30. A sample of size 120 from a normal population has a mean of 40 and a standard deviation of 3.0.
Using the Empirical Rule, about how many items of the sample will be below 34?
____________________
31. A sample of size 100 from a normal population has a mean of 50 and a standard deviation of 5.0.
Using the Empirical Rule, about how many items of the sample will be above 55?
____________________
32. A random sample of speeds was collected by law enforcement of cars traveling through a
particular intersection at 1:00 pm on a Saturday. If the speeds are normally distributed and the mean
was 56 mph with a standard deviation of 4, what percent of the speeds fall between 52 and 60 mph?
____________________
33 – 38. A 9th grade class of 20 students takes a 100 point algebra test. The scores are as follows:
60
64
65
70
72
76
77
78
79
81
82
85
85
85
88
89
92
95
98
99
Determine the following:
33. Mean
34. Median
35. Mode
36. The standard deviation.
37. Would you consider this sample to have a normal distribution?
38. Explain your reasoning for number 37.
39 – 50. The data was collected from a random sample of 20 high school seniors. Math represents the
final exam grade for their math class. GPA represents cumulative GPA for the student. Siblings
represents the number of siblings the student has.
Math
77
65
79
85
71
92
85
64
79
63
88
82
81
99
92
95
94
88
92
71
GPA
2.4
1.7
3.5
3.3
2.5
3.9
2.7
1.9
3.5
1.8
2.7
3.8
3.2
3.9
2.9
3.7
3
2.7
3.4
2.7
Siblings
2
4
4
2
5
1
1
0
0
5
1
2
1
4
5
1
0
0
2
2
39. Is there a correlation between a student’s math exam score and their cumulative GPA?
40. Describe the correlation if there is one.
41. What is the correlation coefficient, r. _______________
42. Perform linear regression analysis on the data. What is the regression equation for predicting
cumulative GPA using math exam scores? _____________________
43. What would be a student’s cumulative GPA if their math exam score was 90? ________
44. How confident are you with the result of this predicted score? Explain your reasoning.
45. Is there a correlation between the number of siblings a student has and their cumulative GPA?
46. Describe the correlation if there is one.
47. What is the correlation coefficient, r. _______________
48. Perform linear regression analysis on the data. What is the regression equation for predicting
cumulative GPA using the number of siblings? _____________________
49. What would be a student’s cumulative GPA if the had 3 siblings? ________
50. How confident are you with the result of this predicted score? Explain your reasoning.