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Free Practice Quiz Question List

6 Descriptive Statistics Online Quiz Questions

Use this free practice quiz with 20 questions to review 6 Descriptive Statistics, test your knowledge, and prepare for your next test or exam.

20 questions
01
True or false
1 point

A frequency table includes every observation in a data set. Apart from possible rounding, the relative frequencies across all categories sum to 100%.

  1. A

    True

  2. B

    False

02
Choose one
1 point

A data set has many distinct numerical values, so an analyst groups them into intervals. What is an important tradeoff of this choice?

  1. A

    It makes it possible to recover every exact observation from the interval counts.

  2. B

    It can make patterns easier to see, but it hides the exact values within each interval.

  3. C

    It guarantees that the data have a symmetric distribution.

  4. D

    It removes the need to consider the number of observations.

03
Fill in the blank
1 point

Relative frequency is a category's frequency divided by the .

04
Choose one
1 point

A researcher has a sample and wants to estimate variability beyond that sample. Which expression gives the sample variance?

  1. A

    ∑(xi−xˉ)2n\frac{\sum (x_i-\bar{x})^2}{n}

  2. B

    ∑(xi−μ)2N\frac{\sum (x_i-\mu)^2}{N}

  3. C

    ∑(xi−xˉ)2n−1\frac{\sum (x_i-\bar{x})^2}{n-1}

  4. D

    ∑(xi−xˉ)2n−1\sqrt{\frac{\sum (x_i-\bar{x})^2}{n-1}}

05
True or false
1 point

A data set can have more than one mode, or no mode when no value occurs more often than the others.

  1. A

    True

  2. B

    False

06
Fill in the blank
1 point

Standard deviation is the of the corresponding variance.

07
Written response
1 point

For the observations 2,3,3,4,4,5,6,132, 3, 3, 4, 4, 5, 6, 13, how many are at or below 4? Enter the count as a number.

08
Choose all
1 point

Select all statements that correctly describe standard deviation.

  1. A

    It is expressed in the same units as the original measurements.

  2. B

    It is expressed in squared units, just like variance.

  3. C

    It is the square root of the corresponding variance.

  4. D

    It is generally unaffected by extreme observations.

09
Written response
1 point

A data set is 4,7,7,12,154, 7, 7, 12, 15. What is its range? Enter the value as a number.

10
Choose all
1 point

A numerical data set is strongly skewed and contains an extreme value. Select the two measures that are often the more resistant choices for describing its center and spread.

  1. A

    Median

  2. B

    Mean

  3. C

    Interquartile range

  4. D

    Standard deviation

11
Choose one
1 point

What is the median of the ordered data set 2,5,7,102, 5, 7, 10?

  1. A

    5

  2. B

    7

  3. C

    6

  4. D

    8

12
Choose one
1 point

A category appears 6 times among 24 observations. What is its relative frequency as a percentage?

  1. A

    6%

  2. B

    25%

  3. C

    30%

  4. D

    75%

13
Written response
1 point

Treat 2,4,6,82, 4, 6, 8 as a sample. What is the sample variance? Enter the exact value as a number or fraction.

14
Open ended
1 point

An analyst reports numerical summaries for a data set and claims that they prove a cause and show that the same pattern holds for a larger population. Explain why those claims do not follow from descriptive statistics alone, and name useful checks or displays that could help interpret the summaries.

15
Choose one
1 point

A survey records respondents' preferred product types, which are categories rather than numerical measurements. Which summary is most appropriate?

  1. A

    The mean and standard deviation

  2. B

    Counts and relative frequencies

  3. C

    The range and interquartile range

  4. D

    The median and variance

16
Choose one
1 point

For the data set 2,3,3,4,4,5,6,132, 3, 3, 4, 4, 5, 6, 13, which value or values are modes?

  1. A

    3 only

  2. B

    4 only

  3. C

    3 and 4

  4. D

    There is no mode

17
Choose one
1 point

You want to inspect the shape, center, and spread of a set of numerical measurements. Which display is best suited to this purpose?

  1. A

    A histogram

  2. B

    A frequency table of category labels only

  3. C

    A list of the data values without ordering

  4. D

    A single mean value

18
Written response
1 point

For the data set 2,3,3,4,4,5,6,132, 3, 3, 4, 4, 5, 6, 13, what is the range? Enter the answer as a number.

19
Choose one
1 point

In the data set 2,3,3,4,4,5,6,132, 3, 3, 4, 4, 5, 6, 13, what is the relative frequency of the value 4?

  1. A

    12.5%12.5\%

  2. B

    25%25\%

  3. C

    40%40\%

  4. D

    50%50\%

20
True or false
1 point

True or false: Variance is expressed in the same units as the original measurements.

  1. A

    True

  2. B

    False