1. What level of measurement is the number of auto accidents reported in a given month?
A. Interval
B. Ratio
C. Nominal
D. Ordinal

2. If two events A and B are mutually exclusive, what does the special rule of addition state?
A. P(A or B)=P(A)-P(B)
B. P(A and/or B)=P(A)+P(B)
C. P(A or B)=P(A)+P(B)
D. P(A and B)=P(A)+P(B)

3. For any data set, which measures of central location have only one value?
A. Mode and standard deviation
B. Mode and mean
C. Mean and median
D. Mode and median

4. What is the variable used to predict the value of another called?
A. Independent variable
B. Correlation variable
C. Variable of determination
D. Dependent variable

5. A null hypothesis makes a claim about a
A. Type II error
B. Population parameter
C. Sample statistic
C. Sample mean

6. The performance of personal and business investments is measured as a percentage, return on investment. What type of variable is return on investment?
A. Continuous
B. Qualitative
C. Attribute
D. Discrete

7. Twenty randomly selected statistics students were given 15 multiple-choice questions and 15 open-ended questions, all on the same material. The professor was interested in determining on which type of questions the students scored higher. This experiment is an example of
Answer: a paired t-test

8. A listing of all possible outcomes of an experiment and their corresponding probability of occurrence is called a
Answer: probability distribution

9. A small sample of computer operators shows monthly incomes of $1,950, $1,775, $2,060, $1,840, $1,795, $1,890, $1,925, and $1,810. What are these ungrouped numbers called?
Answer: Raw data

10. The mean of any uniform probability distribution is
Answer: (a + b)/2

11. Monthly commissions of first-year insurance brokers are $1,270, $1,310, $1,680, $1,380, $1,410, $1,570, $1,180, and $1,420. These figures are referred to as
A. Frequency distribution
B. Frequency polygon
C. a histogram
D. Raw data

12. The test scores for a class of 147 students are computed. What is the location of the test score associated with the third quartile?
A. 111
B. 75%
C. 37
D. 74

13. The names of the positions in a corporation, such as chief operating officer or controller, are examples of what level of measurement?
A. Interval
B. Ratio
C. Nominal
D. Ordinal

14. What is the chart called when the paired data (the dependent and independent variables) are plotted?
A. Pie chart
B. Histogram
C. Scatter diagram
D. Bar chart

15. A sample of single persons receiving social security payments revealed these monthly benefits: $826, $699, $1,087, $880, $839, and $965. How many observations are below the median?
A. 3
B. 1
C. 2
D. 0

16. For a hypothesis test comparing two population means, the combined degrees of freedom are 24. Which of the following statements about the two sample sizes is NOT true? Assume the population standard deviations are equal.
Answer: Sample A=11; sample B=13

17. What type of variable is the number of robberies reported in your city?
A. Attribute
B. Continuous
C. Discrete
D. Qualitative

18. Which of the following conditions must be met to conduct a test for the difference in two sample means?
Answer: Data must be at least of interval scale and populations must be normal

19. Suppose we test the difference between two proportions at the 0.05 level of significance. If the computed z is -1.07, what is our decision?
Answer: Do not reject the null hypothesis

20. The National Center for Health Statistics reported that of every 883 deaths in recent years, 24 resulted from an automobile accident, 182 from cancer, and 333 from heart disease. Using the relative frequency approach, what is the probability that a particular death is due to an automobile accident?
Answer: 24/883 or 0.027

21. For a standard normal distribution, what is the probability that z is greater than 1.75?
Answer: 0.0401

22. The main purpose of descriptive statistics is to
Answer: Summarize data in a useful and informative manner

23. The sum of the deviations of each data value from this measure of central location will always be 0.
A. Standard deviation
B. Median
C. Mean
D. Mode

24. The shape of any uniform probability distribution is
A. Negatively skewed
B. Rectangular
C. Bell shaped
D. Positively skewed

25. What is the level of significance?
A. Beta error
B. Probability of a Type I error
C. z-value of 1.96
D. Probability of a Type II error

26. The measurements of weight of 100 units of a product manufactured by two parallel processes have same mean but the standard of process A is 15 while that of B is 7. What can you conclude?
Answer: The weight of units in process B are grouped closer than in process A

27. For the normal distribution, the mean plus and minus 1.96 standard deviations will include about what percent of the observations?
A. 68%
B. 95%
C. 50%
D. 99.7%

28. A dot plot shows
Answer: The general shape of a distribution

29. The general process of gathering, organizing, summarizing, analyzing, and interpreting data is called
A. inferential statistics
B. Levels of measurement
C. Statistics
D. Descriptive statistics

30. Shoe sizes, such as 7B, 10D, and 12EEE, are examples of what level of measurement?
A. Ordinal
B. Ratio
C. Interval
D. Nominal