Master Descriptive Statistics for Data Science Success

Question 1

Which measure of central tendency is most susceptible to extreme values (outliers)?

Accepted Answer

Mean

Answer

Median

Answer

Mode

Question 2

What does the standard deviation primarily measure?

Accepted Answer

Dispersion of data points

Answer

Central tendency of data points

Answer

Shape of the data distribution

Question 3

Which type of correlation indicates an inverse linear relationship between two variables?

Accepted Answer

Negative correlation

Answer

Positive correlation

Answer

Zero correlation

Question 4

To calculate the range of a dataset, we subtract:

Accepted Answer

Maximum value from minimum value

Answer

Minimum value from maximum value

Answer

Mean from median

Question 5

Which measure of variability is independent of the units of measurement, allowing comparison across different datasets?

Accepted Answer

Coefficient of variation

Answer

Variance

Answer

Standard deviation

Question 6

Which measure summarizes the value that occurs most often in a dataset?

Accepted Answer

Mode

Answer

Mean

Answer

Median

Question 7

Skewness indicates:

Accepted Answer

Direction and degree of data asymmetry

Answer

Symmetry of data around the mean

Answer

Spread of data

Question 8

Which statement is NOT a characteristic of descriptive statistics?

Accepted Answer

Makes inferences about the population

Answer

Summarizes data

Answer

Describes data

Question 9

Which of the following measures is a measure of central tendency, representing the average value of a set of data points?

Accepted Answer

Mean

Answer

Variance

Answer

Correlation coefficient

Question 10

Which of these is NOT a measure of central tendency?

Accepted Answer

Standard Deviation

Answer

Mean

Answer

Median

Answer

Mode

Question 11

Which measure of central tendency indicates the value that appears most frequently in a dataset?

Accepted Answer

Mode

Answer

Mean

Answer

Median

Question 12

To calculate the range of a dataset, which formula should be used?

Accepted Answer

Maximum value minus minimum value

Answer

Sum of all values divided by number of values

Answer

Standard deviation divided by mean

Question 13

Which type of correlation suggests a direct and strong relationship between two variables?

Accepted Answer

Positive

Answer

Negative

Answer

Zero

Question 14

Explain the distinction between a population and a sample in statistics.

Accepted Answer

Population encompasses the entire dataset; sample represents a subset.

Answer

Sample encompasses the entire dataset; population represents a subset.

Question 15

What is the primary purpose of a histogram?

Accepted Answer

To illustrate the distribution of a dataset

Answer

To calculate the mean of a dataset

Answer

To determine if a dataset is normally distributed

Question 16

Which of the following assumptions is NOT necessary for the central limit theorem to hold true?

Accepted Answer

Normally distributed population

Answer

Random sampling

Answer

Sufficiently large sample size

Question 17

What is the main purpose of a box plot?

Accepted Answer

To show the distribution of a dataset and identify outliers

Answer

To calculate the median of a dataset

Answer

To determine if a dataset is normally distributed

Question 18

Which measure of central tendency represents the most commonly occurring value in a dataset?

Accepted Answer

Mode

Answer

Mean

Answer

Median

Answer

Range

Question 19

The standard deviation measures:

Accepted Answer

Dispersion

Answer

Central tendency

Answer

Covariance

Answer

Correlation

Question 20

Which scatterplot indicates a strong positive correlation between two variables?

Accepted Answer

An upward sloping line with data points tightly clustered around the line

Answer

A downward sloping line with data points widely scattered

Answer

A horizontal line with data points evenly distributed

Answer

A vertical line with data points concentrated at one end

Question 21

The range of a dataset is calculated by:

Accepted Answer

Subtracting the maximum value from the minimum value

Answer

Adding the maximum value to the minimum value

Answer

Multiplying the maximum value by the minimum value

Answer

Dividing the maximum value by the minimum value

Question 22

The median of a dataset is:

Accepted Answer

The middle value when arranged in ascending order

Answer

The average of the dataset

Answer

The value that occurs most frequently

Answer

The difference between the maximum and minimum values

Question 23

Which of the following is NOT a characteristic of the normal distribution?

Accepted Answer

Tails extend infinitely in both directions

Answer

Bell-shaped curve

Answer

Symmetrical

Answer

Mean equals median

Question 24

The z-score of a data point measures:

Accepted Answer

How many standard deviations the data point is from the mean

Answer

The probability of observing a data point with that value

Answer

The correlation between the data point and the mean

Answer

The difference between the data point and the median

Question 25

Which type of data cannot be organized into a meaningful order?

Accepted Answer

Nominal

Answer

Numerical

Answer

Ordinal

Answer

Interval

Question 26

What is the difference between the sample mean and the population mean?

Accepted Answer

The sample mean is an unbiased estimate of the population mean.

Answer

The sample mean is always larger than the population mean.

Answer

The sample mean is always smaller than the population mean.

Answer

There is no difference between the sample mean and the population mean.

Question 27

Which measure of dispersion is most sensitive to outliers?

Accepted Answer

Range

Answer

Variance

Answer

Standard deviation

Answer

Coefficient of variation

Question 28

What is the relationship between the mean and the median?

Accepted Answer

The relationship between the mean and the median depends on the distribution of the data.

Answer

The mean is always greater than the median.

Answer

The mean is always less than the median.

Answer

The mean and the median are always equal.

Question 29

What is the purpose of a scatterplot?

Accepted Answer

To show the relationship between two variables.

Answer

To show the distribution of a single variable.

Answer

To compare the means of two groups.

Answer

To test for statistical significance.

Question 30

What is the purpose of a box plot?

Accepted Answer

To show the distribution of a single variable.

Answer

To show the relationship between two variables.

Answer

To compare the means of two groups.

Answer

To test for statistical significance.

Question 31

In a dataset, which measure of central tendency represents the middle value?

Accepted Answer

Median

Answer

Mean

Answer

Mode

Answer

Range

Question 32

Calculate the variance of a dataset using the correct formula:

Accepted Answer

Sum of squared deviations from the mean divided by (n-1)

Answer

Range divided by the standard deviation

Answer

Mean absolute deviation from the median

Answer

Standard deviation squared

Question 33

Identify the option that is not a measure of variability:

Accepted Answer

Mean

Answer

Range

Answer

Kurtosis

Answer

Skewness

Question 34

What does the correlation coefficient primarily assess?

Accepted Answer

Strength and direction of linear relationships

Answer

Difference between two means

Answer

Variance of a dataset

Answer

Significance of statistical tests

Question 35

What is the primary purpose of a box plot?

Accepted Answer

Visualize data distribution and detect outliers

Answer

Calculate mean and standard deviation

Answer

Fit a regression line to the data

Answer

Test for statistical significance

Question 36

For ordinal data, which measure of central tendency is most appropriate?

Accepted Answer

Median

Answer

Mean

Answer

Mode

Answer

Standard deviation

Question 37

How does skewness influence the shape of a distribution?

Accepted Answer

Creates asymmetry with a tail extending either left or right

Answer

Produces a symmetrical, bell-shaped curve

Answer

Results in a uniform distribution with no skewness

Answer

Leads to a multimodal distribution with multiple peaks

Question 38

Which measure of central tendency is heavily influenced by extreme values?

Accepted Answer

Mean

Answer

Median

Answer

Mode

Question 39

For a dataset with no variation, what is its variance?

Accepted Answer

0

Answer

1

Answer

Cannot be determined

Question 40

Which correlation coefficient indicates a negative linear relationship?

Accepted Answer

-1

Answer

Pearson correlation coefficient

Answer

1

Question 41

Which measure of dispersion remains unaffected by the number of observations in a dataset?

Accepted Answer

Coefficient of variation

Answer

Range

Answer

Standard deviation

Question 42

What formula is used to calculate the mean of a dataset?

Accepted Answer

Sum of values / Number of values

Answer

Median of values

Answer

Mode of values

Question 43

Which of the following is not a measure of skewness?

Accepted Answer

Kurtosis

Answer

Pearson's skewness coefficient

Answer

Moment skewness coefficient

Question 44

What does a positive z-score indicate?

Accepted Answer

Data point is above the mean

Answer

Data point is below the mean

Answer

Data point is equal to the mean

Question 45

What is the primary purpose of a stem-and-leaf plot?

Accepted Answer

Displaying the distribution of data

Answer

Identifying outliers

Answer

Calculating summary statistics

Question 46

Describe the possible relationships between the mean, median, and mode of a dataset. Provide an example to illustrate your explanation.

Accepted Answer

In a **symmetric distribution**, the mean, median, and mode are equal.

Accepted Answer

In a **right-skewed distribution**, the mean is greater than the median, which is greater than the mode.

Accepted Answer

In a **left-skewed distribution**, the mean is less than the median, which is less than the mode.

Answer

There is no consistent relationship between the mean, median, and mode.

Question 47

Which measure of central tendency represents the most recurring value in a dataset?

Accepted Answer

Mode

Answer

Mean

Answer

Median

Question 48

What is the deviation of an individual data point from the mean called?

Accepted Answer

Residual

Answer

Kurtosis

Answer

Dispersion

Answer

Range

Question 49

Which type of relationship indicates that as one variable increases, the other variable tends to decrease?

Accepted Answer

Negative correlation

Answer

Linear relationship

Answer

Positive correlation

Answer

Nonlinear relationship

Question 50

What is the commonly used symbol for representing the standard deviation in statistical formulas?

Accepted Answer

σ

Answer

μ

Answer

ρ

Answer

χ

Question 51

What is the key purpose of the empirical rule in statistics?

Accepted Answer

To estimate the proportion of data found within a specified number of standard deviations from the mean.

Answer

To predict the future values of a variable.

Answer

To compare the means of two datasets

Question 52

What is the fundamental difference between population and sample statistics?

Accepted Answer

Population statistics describe the entire population, while sample statistics describe a subset of the population.

Answer

Population statistics are always more accurate than sample statistics.

Question 53

Which scale of measurement is appropriate for data that can be ranked but not measured in absolute terms?

Accepted Answer

Ordinal

Answer

Interval

Answer

Nominal

Question 54

What is the primary purpose of a histogram in descriptive statistics?

Accepted Answer

To visually represent the frequency distribution of continuous data.

Answer

To compare the means of two datasets

Answer

To predict the future values of a variable.