Deck 3: Central Tendency, Variability, and Relative Standing

Question 1

A distribution of data values can be described in terms of all of the following characteristics except:

A) Central tendency
B) Variability
C) Relative standing
D) Shape

Answer 1

C

Question 2

Central tendency indexes are all of the following except which of the following statements?

A) They are descriptive statistics.
B) They summarize how dispersed a set of scores is.
C) They provide information about a value around which scores cluster.
D) They are appropriate for interval- and ratio-level measures.

Answer 2

B

Question 3

In the following distribution (10 11 12 13 14 15 15 15 15) the mode is:

A) 11
B) 12
C) 14
D) 15

Answer 3

D

Question 4

In the following distribution (10 11 12 13 14 15 15 15 15) the median is:

A) 11
B) 12
C) 14
D) 15

Question 5

The median is all of the following except:

A) The 50^th percentile
B) The point that divides a distribution in half
C) Q₂
D) The most popular score in the distribution

Question 6

For which of the following set of numbers are the mean, median, and mode the same value?

A) 1 2 3 3 4 4 4 4 4 5 5 6 7
B) 1 1 2 2 3 3 4 4 5 5 6 6 7 7
C) 1 1 1 2 3 3 4 4 5 5 6 7 7 7
D) All of the above

Question 7

In which type of distribution is the mean a higher value than the median or mode?

A) A leptokurtic distribution
B) A positively skewed distribution
C) A negatively skewed distribution
D) A normal distribution

Question 8

If there are outliers at either end of a distribution that is symmetric, a researcher might:

A) Calculate a trimmed mean
B) Report the median rather than the mean
C) Report the mode rather than the mean
D) Omit the variable from further analyses

Question 9

Which of the following indexes of dispersion is not in the original units of measurement of the variable?

A) Range
B) Interquartile range
C) Standard deviation
D) Variance

Question 10

Which of the following indexes of dispersion tends to be least stable-most likely to fluctuate from one sample to another from the same population?

A) Range
B) IQR
C) Standard deviation
D) Variance

Question 11

Which of the following indexes involves the calculation of deviation scores (x)?

A) Range
B) IQR
C) SD
D) M

Question 12

Which of the following indexes involves the calculation of percentiles?

A) z
B) IQR
C) SD
D) M

Question 13

Which of the following statistical symbols does not belong with the others?

A) SD
B) IQR
C) M
D) μ

Question 14

What percentage of cases for a normally distributed variable lies within 1 SD above and below the mean?

A) 34%
B) 50%
C) 68%
D) 95%

Question 15

In calculating standard scores, which two descriptive statistics are needed?

A) Median, IQR
B) Median, percentiles
C) Mean, Range
D) Mean, SD

Question 16

A z score of 0.00 corresponds to an original score that:

A) Could not be used in the calculation of the mean
B) Is the same as the mean in the original distribution
C) Is the lowest score in the original distribution
D) Is an outlier

Question 17

A z score of -1.00 corresponds approximately to a score for a normally distributed variable that is at the:

A) 1^st percentile
B) 10^th percentile
C) 16^th percentile
D) 84^th percentile

Question 18

An extreme outlier is:

A) More than 3 SDs above the mean
B) Equivalent to a z score of -3.0 or lower, or +3.0 or higher
C) More than three times the value of the mean
D) More than 3 times the IQR, below Q₁ or above Q₃

Question 19

In a boxplot, information about a distribution is depicted in terms of:

A) Percentiles
B) Standard deviation units
C) z scores
D) T scores

Question 20

The number 100 can always be thought of as:

A) A mean of a distribution when the SD is 15
B) A value equivalent to the 10^th percentile
C) A number whose real limits are 99.5 and 100.5
D) An outlier

Question 21

Questions pertain to the following table (Table 3):

-Refer to Table 3. For the variable body mass index, the variance is:

A) 27.0
B) 27.0²
C) 6.0
D) 36.0

Question 22

Questions pertain to the following table (Table 3):

-Refer to Table 3. For the variable number of positive nodes, the statistics suggest that the distribution is:

A) Positively skewed
B) Negatively skewed
C) Symmetric
D) Normal

Question 23

Questions pertain to the following table (Table 3):

-Refer to Table 3. Assume that the distribution for the variable degree of nausea is normally distributed. In such a case, out of the 100 sample members, approximately how many gave a nausea rating of 77 or higher?

A) 0
B) 3
C) 16
D) 34

Question 24

Questions pertain to the following table (Table 3):

-Refer to Table 3. Which variable in Table 3 is most likely to be negatively skewed?

A) Age
B) Body mass index
C) Dose of cyclophosphamide
D) Dose of doxorubicin

Question 25

Questions pertain to the following table (Table 3):

-Refer to Table 3. For the variable body mass index, what would be the standard score for a person whose BMI was 21.0?

A) -1.0
B) 0.0
C) 1.0
D) 2.0