Some Practical Problems Practice Test

For a thorough, step-by-step explanation of similar problems, refer to:

• Frequency Distributions Help
• Variance and Standard Deviation Help
• Probability Help
• Data Intervals Help
• Sampling and Estimation Help
• Hypotheses, Prediction, and Regression Help
• Correlation and Causation Help

Some Practical Problems Practice Test

A good score is 8 correct.

1. Table 8-10 shows the results of a hypothetical quiz given to a class of 130 students. What is wrong with this table?
   1. The absolute frequency values don't add up to 130.
   2. The cumulative absolute frequency values are not added up correctly.
   3. There exists no mean.
   4. There exists no median.
2. Imagine a town in the Northern Hemisphere. In this town, the average monthly rainfall is much greater in the winter than in the summer; the spring and fall months are wetter than the summer months but drier than the winter months. The average monthly temperature is much higher in the summer than in the winter; the spring and fall months are cooler than the summer months but warmer than the winter months.



The correlation between average monthly temperature and average monthly precipitation is

1. positive
2. negative
3. 0
4. impossible to express without more information
3. Suppose that the increase in the incidence of adult-onset diabetes (AOD) in recent years was decreasing, even though the incidence of obesity was increasing. This would logically imply that
   1. weight loss causes AOD
   2. weight gain prevents AOD
   3. AOD causes weight loss
   4. none of the above
4. What is the probability that an unbiased octahedral (8-faceted) die will, if tossed 4 times in a row, come up in the sequence 2, 4, 6, 8, in that order?
   1. 1 in 1024
   2. 1 in 2048
   3. 1 in 4096
   4. 1 in 8192
5. Refer again to the Syndrome X scenario discussed in Problems 8-34 through 8-40. Figure 8-18 is a scatter plot showing the incidence of Syndrome X versus the average annual precipitation in centimeters at the location where each person lives. This plot indicates that there is
   1. no correlation between the incidence of Syndrome X and the average annual precipitation
   2. positive correlation between the incidence of Syndrome X and the average annual precipitation

   

   3. negative correlation between the incidence of Syndrome X and the average annual precipitation
   4. a cause–effect relationship between the incidence of Syndrome X and the average annual precipitation
6. In Fig. 8-18, the least-squares line is not shown, but if it were shown, it would
   1. be horizontal
   2. be vertical
   3. ramp downward as you move toward the right
   4. ramp upward as you move toward the right
7. Suppose you toss an unbiased octahedral die 4 times in a row and you get the sequence 1, 2, 3, 4, in that order. What is the probability that, if you toss the die a fifth time, it will come up showing 5?
   1. 1 in 8
   2. 1 in 16
   3. 1 in 32
   4. 1 in 64
8. Refer to the 10-question quiz taken by 130 students, and discussed in Problems 8-1 through 8-15. Examine Fig. 8-6. Imagine that the quiz is given to another group of 130 students, resulting in the same mean score (μ) but a smaller standard deviation (σ). In this case, the range between μ – σ and μ + σ is
   1. the same as it is in Fig. 8-6
   2. wider than it is in Fig. 8-6
   3. narrower than it is in Fig. 8-6
   4. impossible to determine without more information
9. Refer again to the 10-question quiz taken by 130 students, and discussed in Problems 8-1 through 8-15. Suppose a controversy arises over one of the questions, sparking intense debate and ultimately causing the professor to give everyone credit for the question, as if they all got the answers correct. What effect would this have on the general shape of the graph shown in Fig. 8-6?
   1. It would skew the graph slightly to the right.
   2. It would skew the graph slightly to the left.
   3. It would slightly flatten out the graph.
   4. It would not have any effect on the general shape of the graph.
10. Refer one last time to the 10-question quiz taken by 130 students, and discussed in Problems 8-1 through 8-15. Suppose that all the scores were 5 correct, 6 correct, or 7 correct; no one got less than 5 correct nor more than 7 correct. What effect would this have on the general shape of the graph shown in Fig. 8-6?
    1. It would not have any effect on the general shape of the graph.
    2. It would cause the graph to be more sharply peaked.
    3. It would cause the graph to be more flattened out.
    4. There is no way to know, without more information, what would happen to the general shape of the graph.

Answers

1. b
2. b
3. d
4. c
5. b
6. d
7. a
8. c
9. a
10. b