Master Descriptive Statistics: A Key to Data Analysis

Question 1

Which measure of central tendency is least affected by outliers?

Accepted Answer

Median

Answer

Range

Answer

Mode

Answer

Mean

Question 2

What is the formula for calculating the sample standard deviation?

Accepted Answer

√[Σ(x - μ)² / (n - 1)]

Answer

n / Σ(x - μ)²

Answer

Σ(x - μ)² / n

Answer

Σ(x - μ)²

Question 3

Which of the following statistical concepts does NOT summarize the central tendency of data?

Accepted Answer

Probability distribution

Answer

Mode

Answer

Mean

Answer

Median

Question 4

What is the main purpose of calculating the range of a data set?

Accepted Answer

To measure the spread or variability of the data

Answer

To find the most frequently occurring value

Answer

To determine the central tendency of the data

Answer

To calculate the probability of occurrence

Question 5

Which measure of central tendency is most affected by extreme values?

Accepted Answer

Mean

Answer

Median

Answer

Mode

Answer

Range

Question 6

Which of the following is a measure of variability, not central tendency?

Accepted Answer

Range

Answer

Mean

Answer

Median

Answer

Mode

Question 7

How do descriptive statistics contribute to hypothesis formulation for further statistical testing?

Accepted Answer

By analyzing data distribution and variability to guide the selection of appropriate statistical tests.

Answer

By directly testing hypotheses using descriptive statistics, eliminating the need for inferential tests.

Question 8

Which measure of central tendency is most sensitive to extreme values?

Accepted Answer

Mean

Answer

Median

Answer

Standard deviation

Answer

Mode

Question 9

What is the formula for calculating the standard deviation?

Accepted Answer

√[Σ(x - μ)² / (N-1)]

Answer

μ / Σ(x - μ)²

Answer

Σ(x - μ)² / N

Question 10

Which of the following is a measure of data dispersion?

Accepted Answer

Range

Answer

Mode

Answer

Median

Answer

Mean

Question 11

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

Accepted Answer

To visually display the distribution of data

Answer

To calculate the mean

Answer

To plot a regression line

Answer

To find the mode

Question 12

Which of the following is NOT an advantage of using descriptive statistics?

Accepted Answer

They can be used to predict future values

Answer

They provide a concise summary of data

Answer

They are easy to calculate

Answer

They can be used to identify patterns and relationships

Question 13

What is the difference between a parameter and a statistic?

Accepted Answer

A parameter describes a characteristic of a population, while a statistic describes a characteristic of a sample.

Answer

Parameters are always known, while statistics are always estimated

Answer

A statistic describes a characteristic of a population, while a parameter describes a characteristic of a sample

Question 14

In a symmetrical distribution, what is the relationship between mean, median, and mode?

Accepted Answer

They are all equal

Answer

The mean is always greater than the median

Answer

The median is always equal to the mode

Question 15

Which measure of central tendency represents the average value of a data set?

Accepted Answer

Mean

Answer

Median

Answer

Range

Answer

Mode

Question 16

What is the purpose of a box plot?

Accepted Answer

To display the median, quartiles, and potential outliers of a data set.

Answer

To compare the distributions of two or more data sets.

Answer

To calculate the mean and standard deviation of a data set.

Question 17

A data set has a mean of 10 and a variance of 25. What is the standard deviation of the data set?

Accepted Answer

5

Answer

25

Answer

2

Answer

10

Question 18

Which of the following is a statistical measure that quantifies the asymmetry of a distribution?

Accepted Answer

Skewness coefficient

Answer

Standard deviation

Answer

Kurtosis coefficient

Question 19

Which of the following is a potential limitation of using descriptive statistics?

Accepted Answer

Descriptive statistics can oversimplify complex data distributions, potentially concealing important patterns or outliers.

Answer

Descriptive statistics are always accurate and reliable.

Answer

Descriptive statistics can be used to draw inferences about a population.

Question 20

What is the fundamental distinction between descriptive and inferential statistics?

Accepted Answer

Descriptive statistics summarize and describe data, while inferential statistics make inferences and draw conclusions about a larger population based on a sample.

Answer

Descriptive statistics use numerical measures, while inferential statistics use graphical representations.

Question 21

Which of the following is not a measure of central tendency?

Accepted Answer

Standard deviation

Answer

Median

Answer

Mean

Answer

Mode

Question 22

The arithmetic mean of a dataset is computed by:

Accepted Answer

Summing all values and dividing by the total number of values.

Answer

Selecting the value that appears most frequently.

Answer

Calculating the difference between the maximum and minimum values.

Answer

Arranging the data in ascending order and selecting the middle value.

Question 23

When analyzing skewed data, which measure of central tendency is generally more appropriate?

Accepted Answer

Median

Answer

Mode

Answer

Standard deviation

Answer

Mean

Question 24

The range of a dataset refers to:

Accepted Answer

The difference between the maximum and minimum values.

Answer

The sum of all values.

Answer

The average of all values.

Question 25

The standard deviation primarily measures:

Accepted Answer

The spread or dispersion of data points relative to the mean.

Answer

The number of values in the dataset.

Answer

The difference between the maximum and minimum values.

Answer

The central value or tendency of the data.

Question 26

Which of the following is not an advantage of using descriptive statistics?

Accepted Answer

Descriptive statistics cannot be used to make inferences or draw conclusions about the entire population from which the data was sampled.

Answer

Descriptive statistics provide a concise summary of data.

Answer

Descriptive statistics help identify patterns and trends in the data.

Question 27

The interquartile range (IQR) is:

Accepted Answer

Difference between the third quartile (Q3) and the first quartile (Q1)

Answer

Sum of all quartiles

Answer

Measure of central tendency

Question 28

The coefficient of variation (CV) is a measure of:

Accepted Answer

Relative variability

Answer

Absolute variability

Answer

Correlation

Answer

Central tendency

Question 29

Skewness measures the:

Accepted Answer

Asymmetry of a distribution

Answer

Central tendency of a distribution

Answer

Mode of a distribution

Answer

Spread of a distribution

Question 30

Which measure of central tendency is most resilient to outliers?

Accepted Answer

Median

Answer

Mean

Answer

Standard deviation

Answer

Mode

Question 31

A data set has values of 5, 7, 9, 11, and 13. What is its mode?

Accepted Answer

5, 7, 9, 11, and 13

Answer

13

Answer

5

Answer

9

Question 32

A normal distribution has a mean of 10 and a standard deviation of 2. What is the probability of randomly selecting a value between 8 and 12?

Accepted Answer

0.6827

Answer

0.3173

Answer

0.0548

Answer

0.1359

Question 33

Which of the following is NOT a characteristic of a box plot?

Accepted Answer

It shows the actual data points.

Answer

It shows the outliers.

Answer

It shows the quartiles.

Answer

It shows the median.

Question 34

What is theIQR(Interquartile range) of the data set: 1, 3, 5, 7, 9, 11, 13, 15?

Accepted Answer

6

Answer

12

Answer

10

Answer

8

Question 35

Which measure of skewness indicates a distribution that is skewed to the right?

Accepted Answer

Positive

Answer

Zero

Answer

Negative

Question 36

What is the covariance between two variables X and Y if their correlation coefficient is 1?

Accepted Answer

Positive and equal to the product of their standard deviations

Answer

Zero

Answer

Negative and equal to the product of their variances

Question 37

Which of the following is a limitation of descriptive statistics?

Accepted Answer

It cannot make predictions about future events

Answer

It is always accurate

Answer

It can be used to test hypotheses

Answer

It can provide insights into the underlying data-generating process

Question 38

What is the purpose of descriptive statistics in data analysis?

Accepted Answer

To summarize and present data in a concise and meaningful way

Answer

To predict future events

Answer

To make inferences about a population

Question 39

Which measure of central tendency is most affected by outliers?

Accepted Answer

Mean

Answer

Standard deviation

Answer

Median

Answer

Mode

Question 40

A company has an employee satisfaction survey with a mean of 85% and a median of 90%. Which conclusion can be drawn about the distribution of the data?

Accepted Answer

It is positively skewed.

Answer

It cannot be determined.

Answer

It is normally distributed.

Answer

It is negatively skewed.

Question 41

Which statistic measures the variability of a dataset?

Accepted Answer

Standard deviation

Answer

Mode

Answer

Median

Answer

Mean

Question 42

A normal distribution has a mean of 50 and a standard deviation of 10. What is the z-score for a value of 60?

Accepted Answer

1

Answer

0

Answer

2

Answer

0.5

Question 43

Which of the following is NOT a measure of shape for a distribution?

Accepted Answer

Standard deviation

Answer

Skewness

Answer

Kurtosis

Answer

Median

Question 44

A dataset has a mean of 100 and a standard deviation of 20. What is the probability of randomly selecting a value between 80 and 120?

Accepted Answer

0.6827

Answer

0.1587

Answer

0.8413

Answer

0.3173

Question 45

Which of the following is a measure of dispersion that is not affected by outliers?

Accepted Answer

Median Absolute Deviation

Answer

Variance

Answer

Range

Answer

Standard deviation

Question 46

Which of the following measures of central tendency is most affected by extreme values?

Accepted Answer

Mean

Answer

Median

Answer

Standard deviation

Answer

Mode

Question 47

A dataset has a mean of 10 and a standard deviation of 2. What is the z-score for a value of 12 in this dataset?

Accepted Answer

1

Answer

0.5

Answer

2

Question 48

Which of the following is NOT a measure of dispersion?

Accepted Answer

Mean

Answer

Interquartile range

Answer

Range

Question 49

A histogram represents the distribution of a dataset by:

Accepted Answer

Dividing the range of values into equal intervals and counting the number of data points in each interval

Answer

Plotting the individual data points in a scatterplot

Question 50

Which of the following shapes on a histogram indicates a dataset with a high degree of skewness?

Accepted Answer

Asymmetrical, with one tail extending further than the other

Answer

Symmetrical, with a bell-shaped curve

Answer

Flat, with a uniform distribution of data points

Question 51

Which of the following is a limitation of using mean as a measure of central tendency?

Accepted Answer

It can be distorted by outliers

Answer

It is not a robust measure

Answer

It is not suitable for ordinal data

Answer

It is not interpretable without context

Question 52

A box plot can be used to determine:

Accepted Answer

The median, interquartile range, and presence of outliers

Answer

The mode and range

Answer

The mean and standard deviation

Question 53

Which of the following statistical measures represents the spread of data?

Accepted Answer

Standard deviation

Answer

Median

Answer

Mean

Answer

Mode

Question 54

The coefficient of variation (CV) is a measure of:

Accepted Answer

Relative variability

Answer

Central tendency

Answer

Skewness

Answer

Absolute variability

Question 55

Which of the following distributions is characterized by a bell-shaped curve?

Accepted Answer

Normal distribution

Answer

Bimodal distribution

Answer

Skewed distribution

Answer

Uniform distribution