QUESTIONS FOR THE FINAL:
1. Numbers that describe a population are called:
a. Mean
b. Statistic
c. Parameter
d. Sample
2. The most common way to display the relation between two quantitative variables is:
a. Stem and leaf
b. Histogram
c. Scatterplot
d. Box plot
3. The correlation r has values
a. r > 0
b. r < 0
c. -1 ≤ r ≤ 1
d. r is between 0 and 100
4. Which of the following cannot be a correlation?
a. -2.25
b. +0.25
c. -0.80
d. +0.80
5. A straight line that is drawn through a scatterplot to summarize the relationship between explanatory and response variables is called:
a. Correlation line
b. Standard deviation line
c. Regression line
d. None of the above
6. The best evidence of causation comes from
a. Surveys
b. Observational studies
c. Experiments
d. None of the above
7. The Aimco Job Placement Agency gathers data from a survey about the number of years of college and their clients’ starting salaries. The results were tabulated and a least squares regression line was generated. The regression equation y = 11.44x + 8.2 represents the relationship between number of college years experience (x) and starting salary (y) (in thousands). The r2 value is .888.
A) Use the regression equation to determine the starting salary of someone who has 6 years of college experience.
a. 68.64 thousand dollars
b. 76.84 thousand dollars
c. 8.2 thousand dollars
d. 11.44 thousand dollars
B). What would be the starting salary if you had no college experience?
a. 8.2 thousand dollars
b. 11.44 thousand dollars
c. 0 dollars
d. Cannot be determined from information given.
C). The r2 value tells us that:
a. It is a weak correlation
b. It is a negative correlation
c. Approximately 89% of the observed variation is explained by the straight-line data.
d. There is extreme variation observed in starting salaries.
8. If individual outcomes are uncertain but there is a regular distribution of outcomes in a large number of repetitions we call the phenomenon:
a. Probability
b. Random
c. Predictable
d. None of the above
9. The range of values of probability is:
a. -1 to 1
b. 0 to 100
c. 0 to 1
d. -100 to 100
10. Probability that the toss of coin will land on tails.
a. 0
b. 0.2
c. 0.5
d. 1.0
11. Probability that it will snow when it’s 10 degrees outside.
a. 0
b. 0.2
c. 0.5
d. 1.0
12. A _______________ describes how we assign probabilities to a collection of outcomes.
a. Probability distribution
b. Probability model
c. Sampling
d. Sampling distribution
13. Use the following information to answer questions #4-7
If you draw a chocolate truffle from a bag of chocolates, the one you draw will have one of five flavors. The probability of drawing each truffle depends on the proportion of each flavor among all flavors made. Here are the probabilities of each flavor for a randomly chosen bag of chocolates:
Flavor Probability
Raspberry 0.25
Dark Chocolate 0.3
Mint 0.2
Peanut Butter 0.15
White Chocolate ?
A). What is the p(white chocolate)?
a. 0.25
b. 0.1
c. 0.15
d. None of the above
B). What is the p(not raspberry)?
a. 0.25
b. 0.65
c. 0.75
d. None of the above
C). What is the p(dark chocolate or peanut butter)?
a. .045
b. 0.25
c. 0.45
d. None of the above
D). What is the p(orange)?
a. 0.15
b. 0.10
c. 0.25
d. None of the above
14. The expected value is:
a. Average of all possible outcomes
b. Sum of the products of numerical outcomes and their respective probabilities
c. All of these
d. None of the above
16. The expected value of a six-sided fair die (all outcomes equally likely)
a. 1/6
b. 3.0
c. 3.5
17. ___________ states that the mean outcome in many repetitions gets close to the expected value.
a. Independent events
b. Law of Large Numbers
c. Gambling
18. Use the following situation to answer questions #A and B.
On a multiple-choice test, a student has four possible choices for each question. The student receives 1 point for a correct answer and loses ¼ point for an incorrect answer.
A). If the student has no idea of the correct answer for a particular question and merely guesses, what is p(getting the correct answer) and p(choosing incorrectly)?
a. p(correct) = 0.25; p(incorrect) = 0.75
b. p(correct) = 0.75; p(incorrect) = 0.25
c. p(correct) = 0.5; p(incorrect) = 0.5
B). If the student has no idea of the correct answer for a particular question and merely guesses, what is the student’s expected gain or loss on the question?
a. 0.0625
b. -0.0625
c. None of the above
19. A newspaper poll on state budgetary issues interviewed 828 state residents. Of the residents surveyed, 470 of them felt that the state should balance the budget. Use the poll results to give a 95% confidence interval for p.
a. 0.5676
b. 0.0172
c. 0.5504 to 0.5848
d. 0.5332 to 0.602
20. True or False: As our sample size increases, our power increases.
a. True
b. False
21. A confidence interval:
a. Tells us how uncertain the estimate is.
b. Says how closely we can pin down an unknown parameter.
c. Helps to answer the question, “How good is the statistic as an estimate of the parameter?”
d. All of the above.
e. None of the above.
22. A confidence interval for a parameter has:
a. An interval calculated from the data.
b. A confidence level which gives the probability that the interval will capture the true parameter value in repeated samples.
c. Both a and b
d. Neither a or b
23. The Alternative Hypothesis is one-sided if:
a) it has a sign of <
b) it has a sign of >
c) it has a sign of ¹
d) all of the above
e) only a) and b)
24. Which of the hypothesis tests on “no difference”, “no effect”
a) Null, H0
b) Alternative, HA
25. The first question to ask in any statistical study is:
a. What is the confidence level?
b. Where do the data come from?
c. What does the statistical inference say?
d. What are the measures of central tendency?
26. The purpose of significance tests is to:
a. Weigh the evidence that the data gives
b. Answer the question, “How true is the null hypothesis?”
c. Both a and b
d. Neither a nor b
27. ________ estimate a population parameter and are easy to interpret.
a. Significance tests
b. Confidence intervals
c. Null hypothesis
d. P-value
28. The purpose of a test of significance is to:
a. Describe the degree of evidence provided by the sample against the null hypothesis. A large P-value does this.
b. Describe the degree of evidence provided by the sample against the null hypothesis. A small P-value does this.
c. Describe the degree of evidence provided by the population against the null hypothesis. A large P-value does this.
d. Describe the degree of evidence provided by the population against the null hypothesis. A small P-value does this.