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web.groovymark@gmail.com
- November 21, 2024
Question 21
What does a box plot display in a dataset?
a) The average of the data
b) The spread and center of the data, along with outliers
c) The total number of data points
d) The relationship between two variables
Correct Answer: b) The spread and center of the data, along with outliers
Explanation: Box plots visually summarize the distribution of data points, indicating the median, quartiles, and any potential outliers.
Question 22
What does “sampling error” represent?
a) The total count of samples taken
b) The difference between the sample statistic and the true population parameter
c) The average value of a sample
d) The method used to collect data
Correct Answer: b) The difference between the sample statistic and the true population parameter
Explanation: Sampling error occurs due to variability between the sample and the population from which it is drawn, affecting the accuracy of estimates.
Question 23
In Excel, which function is used to find the lowest value in a range?
a) =AVERAGE
b) =SUM
c) =MIN
d) =COUNT
Correct Answer: c) =MIN
Explanation: The MIN function identifies the smallest value from a specified range of numbers in Excel.
Question 24
What does “data enrichment” involve?
a) Removing irrelevant data
b) Adding relevant external data to existing datasets
c) Summarizing data for easy access
d) Normalizing datasets for consistency
Correct Answer: b) Adding relevant external data to existing datasets
Explanation: Data enrichment improves datasets by incorporating additional relevant information, providing a deeper understanding of the data.
Question 25
When analyzing data, what is the primary use of “cross-tabulation”?
a) To visualize trends
b) To summarize relationships between two categorical variables
c) To clean data
d) To perform statistical tests
Correct Answer: b) To summarize relationships between two categorical variables
Explanation: Cross-tabulation creates a matrix format that displays how two categorical variables relate to one another, facilitating comparative analysis.
Question 26
How is the “interquartile range” (IQR) calculated?
a) By averaging all values in the dataset
b) By subtracting the first quartile (Q1) from the third quartile (Q3)
c) By finding the median of the dataset
d) By calculating the range of the dataset
Correct Answer: b) By subtracting the first quartile (Q1) from the third quartile (Q3)
Explanation: The IQR measures the spread of the middle 50% of data, indicating variability and helping to identify potential outliers.
Question 27
What does a “scatter plot” primarily illustrate?
a) The average of a dataset
b) The relationship between two quantitative variables
c) The frequency of categories
d) The parts of a whole
Correct Answer: b) The relationship between two quantitative variables
Explanation: Scatter plots depict individual data points for two quantitative variables, allowing for analysis of correlations and relationships.
Question 28
In Excel, what does the COUNTIF function do?
a) Counts all cells in a range
b) Counts cells based on a specific condition
c) Calculates the average of a range
d) Finds the maximum value in a range
Correct Answer: b) Counts cells based on a specific condition
Explanation: The COUNTIF function allows users to count the number of cells within a range that meet a specified criterion, enabling targeted analysis.
Question 29
What is the role of a “data dashboard”?
a) To manipulate data
b) To visualize key metrics and performance indicators
c) To store raw data
d) To delete unneeded data
Correct Answer: b) To visualize key metrics and performance indicators
Explanation: Data dashboards aggregate important metrics and present them visually, facilitating quick insights and effective decision-making.
Question 30
How can “data cleaning” improve the accuracy of analysis?
a) By removing duplicate entries and correcting errors
b) By summarizing the data
c) By visualizing trends
d) By categorizing data into groups
Correct Answer: a) By removing duplicate entries and correcting errors
Explanation: Data cleaning enhances the quality of data by eliminating inaccuracies, which is crucial for valid and reliable analysis.
Question 31
What does “skewness” indicate about a dataset?
a) The central tendency
b) The symmetry of the data distribution
c) The total number of observations
d) The spread of data
Correct Answer: b) The symmetry of the data distribution
Explanation: Skewness measures the extent to which a distribution deviates from symmetry, indicating whether data points are concentrated on one side of the mean.
Question 32
Which type of sampling ensures that each member of the population has an equal chance of being selected?
a) Stratified sampling
b) Cluster sampling
c) Random sampling
d) Convenience sampling
Correct Answer: c) Random sampling
Explanation: Random sampling gives all individuals in the population an equal opportunity to be included in the sample, enhancing representativeness.
Question 33
What is the main purpose of a “histogram”?
a) To show relationships between variables
b) To display the distribution of numerical data
c) To summarize categorical data
d) To compare two datasets
Correct Answer: b) To display the distribution of numerical data
Explanation: Histograms visualize the frequency distribution of numerical data across defined intervals, illustrating how data is spread.
Question 34
How is “data normalization” beneficial for datasets?
a) It removes outliers.
b) It allows for consistent comparisons across different datasets.
c) It categorizes data.
d) It aggregates data into summary statistics.
Correct Answer: b) It allows for consistent comparisons across different datasets.
Explanation: Normalization adjusts data to a common scale, enabling effective comparisons and analyses between different datasets.
Question 35
What does a box plot reveal about a dataset?
a) The total number of data points
b) The spread and center of the data
c) The average value of the dataset
d) The relationship between two variables
Correct Answer: b) The spread and center of the data
Explanation: A box plot summarizes the distribution of data points, including the median, quartiles, and potential outliers, providing a visual representation of spread.
Question 36
Which statistical test is appropriate for analyzing the difference between the means of three or more groups?
a) T-test
b) ANOVA
c) Chi-square test
d) Regression analysis
Correct Answer: b) ANOVA
Explanation: ANOVA (Analysis of Variance) compares the means of three or more groups to determine if at least one group mean is statistically different from the others.
Question 37
What is the purpose of a “legend” in data visualization?
a) To summarize data
b) To describe the data series and corresponding colors or patterns
c) To calculate averages
d) To manipulate data
Correct Answer: b) To describe the data series and corresponding colors or patterns
Explanation: The legend clarifies the meaning of colors or patterns used in a chart, helping viewers interpret the data correctly.
Question 38
What does “data enrichment” enhance in a dataset?
a) Accuracy
b) Volume
c) Relevance
d) Complexity
Correct Answer: c) Relevance
Explanation: Data enrichment adds relevant information from external sources, making the dataset more valuable and insightful for analysis.
Question 39
In Excel, what does the function =SUMIF(range, criteria) accomplish?
a) Counts cells based on a condition
b) Sums cells that meet a specified criterion
c) Finds the average of a range
d) Identifies the maximum value
Correct Answer: b) Sums cells that meet a specified criterion
Explanation: The SUMIF function allows users to add up values in a range that meet specific criteria, facilitating targeted data aggregation.
Question 40
When analyzing categorical data, which statistical method is most appropriate?
a) Regression analysis
b) Chi-square test
c) T-test
d) ANOVA
Correct Answer: b) Chi-square test
Explanation: The chi-square test evaluates whether there is a significant association between categorical variables, helping to analyze relationships in categorical data.
