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statistics Test 2 Chp 7, 8, 9, 10, 11 > chapter 7 > Flashcards

Flashcards in chapter 7 Deck (22)
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1

5. Which of the following measures of center is affected by an outlier?


a. Mean
b. Median
c. Mode
d. All of the above

A

2

6. The mode is most meaningful for which type of data?


a. Measurement data
b. Categorical data
c. Biased data
d. None of the above

B

3

7. The amount of spread in the data is a measure of what characteristic of a data set?


a. Center
b. Variability
c. Shape
d. None of the above

B

4

8. What is the simplest measure of variability in a data set?


a. The interquartile spread
b. The outliers
c. The range
d. The standard deviation

C

5

15. Which of the following pictures of a data set allows you to retrieve the actual data (assuming no digits are dropped)?


a. A histogram
b. A stemplot
c. Both a) and b)
d. Neither a) nor b)

B

6

16. If the bars of a histogram represent the proportion of the total count that falls into each interval, what must the heights of the bars sum to?


a. The total number of numbers in the data set.
b. One.
c. 1 divided by the total number of intervals used in the histogram.
d. Not enough information to tell.

B

7

17. Which of the following statements is true?


a. If a data set is skewed to the right, that means there is bias in the results; the data are higher than they should be.
b. If a data set is skewed to the right, then the higher values are more spread out than the lower values.
c. If a data set is skewed to the right, then the lower values are more spread out than the higher values.
d. None of the above.

B

8

18. Which of the following statements regarding stemplots is false?


a. A stemplot allows you to retrieve the original data (assuming no digits are dropped).
b. A stemplot can never reuse the same stem digit twice.
c. If a certain value in your data set is repeated three times, it must appear 3 times in appropriate stem and leaf of the stemplot.
d. None of the above statements are false.

B

9

25. Suppose that in a five-number summary you find that a larger gap exists between the third quartile and the highest value than between the lowest value and the first quartile. What does this mean about the shape of the data set?


a. Symmetric
b. Skewed right
c. Skewed left
d. Not enough information to tell.

B

10

26. Suppose that in a five-number summary you find that a larger gap exists between the extremes and the quartiles than between the quartiles and the median. What does this mean about the shape of the data set?


a. The data are clumped at the high and low ends.
b. The data are clumped in the middle.
c. The data are not symmetric.
d. Not enough information to tell.

B

11

27. Which of the following does not require the data to be ordered before you can get the right answer?


a. Mean
b. Median
c. Quartiles
d. Range
e. All of the above require the data to be ordered.

A

12

28. Which of the following is not included in the five-number summary?


a. Mean
b. Median
c. Lower quartile
d. Highest number
e. All of the above are included in the five-number summary.

A

13

35. How do you calculate the interquartile range for a data set?


a. Take the highest value minus the lowest value and divide it by four.
b. Subtract the value of the lower quartile from the upper quartile.
c. Subtract the value of the upper quartile from the lower quartile.
d. Divide the data set into four equal parts and find the range between each of the resulting quarters.

B

14

36. If the width of a box in a boxplot is very large, compared to the rest of the boxplot, what does that mean about the shape of the data set?


a. The data are very spread out in the middle.
b. The data are clumped tightly in the middle.
c. The data are not symmetric.
d. Not enough information to tell.

A

15

37. Suppose you look at two boxplots comparing the weights of male cats vs. female cats, and you find that the box for the males is much wider than the box for the females. What does this mean about the data sets?


a. Male cats weigh more than female cats overall.
b. Male cats have more variability in their weights than female cats.
c. Weights of male cats are more skewed than for female cats.
d. None of the above.

B

16

38. Which of the following can not be obtained from a boxplot?


a. Mean
b. Median
c. IQR
d. Range
e. All of the above can be obtained from a boxplot.

A

17

45. What is the relationship between the variance and the standard deviation?


a. The variance is the square root of the standard deviation.
b. The variance is the square of the standard deviation.
c. The variance is twice the standard deviation.
d. There is no relationship between them.

B

18

46. Suppose a data set is skewed left. What is the most likely relationship between the mean and the median?


a. The mean is larger than the median.
b. The mean is smaller than the median.
c. The mean and the median are not related to each other at all.
d. The mean and the median are essentially equal.

B

19

47. Which of the following statements is false?


a. If the standard deviation is positive, the mean must be positive.
b. The standard deviation can be negative.
c. If the mean is large, the standard deviation will be large also.
d. All of the above are false.

D

20

48. Which of the following is not a measure of spread or variability in a data set?


a. Standard deviation
b. IQR
c. Range
d. All of the above are measures of spread or variability in a data set.

D

21

53. Which of the following statements is statistically correct?


a. “Jimmy is taller than normal for a two-year old.”
b. “Jimmy is taller than the average two-year old.”
c. “Jimmy is taller than the average height of two-year olds.”
d. All of the above are statistically correct.

C

22

54. Which of the following methods is the most appropriate one for ‘proving’ someone cheated on a multiple choice exam who was allegedly looking at someone else’s paper?


a. Examine the two papers and see how many questions they both got wrong, and how many times the same wrong answer was chosen for those questions.

b. Take the student’s paper that was allegedly copied from (student X) and compare it to all other students’ papers in the class. Take the number of answers that each student matched with student X and make a histogram. Then see where the alleged cheater fell on the resulting histogram.

c. Neither of these methods is appropriate. There is always a chance that two people could have the same answers but no cheating was going on.

d. Both of these methods are equivalent, so either one is appropriate.

C