CompTIA DA0-001 CompTIA Data+ Certification Online Training

Question #61

A cereal manufacturer wants to determine whether the sugar content of its cereal has increased over the years.

Which of the following is the appropriate descriptive statistic to use?

A . Frequency
B . Percent change
C . Variance
D . Mean

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Question #62

The process of performing initial investigations on data to spot outliers, discover patterns, and test assumptions with statistical insight and graphical visualization is called:

A . a t-test.
B . a performance analysis.
C . an exploratory data analysis.
D . a link analysis.

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Correct Answer: C
C

Explanation:

This is because exploratory data analysis is a type of process that performs initial investigations on data to spot outliers, discover patterns, and test assumptions with statistical insight and graphical visualization, such as box plots, histograms, scatter plots, etc. Exploratory data analysis can be used to understand and summarize the data, as well as to generate hypotheses or questions for further analysis or research. For example, exploratory data analysis can be used to identify and visualize the characteristics, features, or behaviors of the data, as well as to measure their distribution, frequency, or correlation. The other options are not types of processes that perform initial investigations on data to spot outliers, discover patterns, and test assumptions with statistical insight and graphical visualization. Here is what they mean:

A t-test is a type of statistical method that tests whether there is a significant difference between the means of two groups or samples, such as whether there is a difference between the average exam scores of two classes in this case. A t-test can be used to test or verify a claim or an assumption about the data, as well as to measure the confidence or the error of the estimation.

A performance analysis is a type of process that measures whether the data meets certain goals or objectives, such as targets, benchmarks, or standards. A performance analysis can be used to identify and visualize the gaps, deviations, or variations in the data, as well as to measure the efficiency, effectiveness, or quality of the outcomes. For example, a performance analysis can be used to determine if there is a gap between a student’s test score and their expected score based on their previous performance.

A link analysis is a type of process that determines whether the data is connected to other datapoints, such as entities, events, or relationships. A link analysis can be used to identify and visualize the patterns, networks, or associations among the datapoints, as well as to measure the strength, direction, or frequency of the connections. For example, a link analysis can be used to determine if there is a connection between a customer’s purchase history and their loyalty program status.

Question #63

Different people manually type a series of handwritten surveys into an online database.

Which of the following issues will MOST likely arise with this data? (Choose two.)

A . Data accuracy
B . Data constraints
C . Data attribute limitations
D . Data bias
E . Data consistency
F . Data manipulation

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Question #64

Which of the following data sampling methods involves dividing a population into subgroups by similar characteristics?

A . Systematic
B . Simple random
C . Convenience
D . Stratified

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Question #65

A data analyst must separate the column shown below into multiple columns for each component of the name:

Which of the following data manipulation techniques should the analyst perform?

A . Imputing
B . Transposing
C . Parsing
D . Concatenating

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Question #66

Which of the following descriptive statistical methods are measures of central tendency? (Choose two.)

A . Mean
B . Minimum
C . Mode
D . Variance
E . Correlation
F . Maximum

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Question #67

Which of the following will MOST likely be streamed live?

A . Machine data
B . Key-value pairs
C . Delimited rows
D . Flat files

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Question #68

A database consists of one fact table that is composed of multiple dimensions. Depending on the dimension, each one can be represented by a denormalized table or multiple normalized tables.

This structure is an example of a:

A . transactional schema.
B . star schema.
C . non-relational schema.
D . snowflake schema.

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Question #69

A data analyst is designing a dashboard that will provide a story of sales and determine which site is providing the highest sales volume per customer. The analyst must choose an appropriate chart to include in the dashboard.

The following data is available:

Which of the following types of charts should be considered?

A . Include a line chart using the site and average sales per customer.
B . Include a pie chart using the site and sales to average sales per customer.
C . Include a scatter chart using sales volume and average sales per customer.
D . Include a column chart using the site and sales to average sales per customer.

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Correct Answer: C
C

Explanation:

A scatter chart using sales volume and average sales per customer is the best type of chart to include in the dashboard. A scatter chart is a type of chart that displays the relationship between two numerical variables using dots or markers. A scatter chart can show how one variable affects another, how strong the correlation is between them, and how the data points are distributed. In this case, a scatter chart can show the story of sales and determine which site is providing the highest sales volume per customer by plotting the sales volume on the x-axis and the average sales per customer on the y-axis. Each dot on the chart will represent a site, and the analyst can easily compare the sites based on their position on the chart. A site with a high sales volume and a high average sales per customer will be in the upper right quadrant, indicating a high performance. A site with a low sales volume and a low average sales per customer will be in the lower left quadrant, indicating a low performance. A site with a high sales volume and a low average sales per customer will be in the lower right quadrant, indicating a high volume but low value. A site with a low sales volume and a high average sales per customer will be in the upper left quadrant, indicating a low volume but high value. A scatter chart can also show if there is a positive or negative correlation between the two variables, or if there is no correlation at all. A positive correlation means that as one variable increases, so does the other. A negative correlation means that as one variable increases, the other decreases. No correlation means that there is no relationship between the two variables.

The other types of charts are not as suitable for this purpose. A line chart is a type of chart that displays the change of one or more variables over time using lines. A line chart can show trends, patterns, and fluctuations in the data. However, in this case, there is no time variable involved, so a line chart would not be appropriate. A pie chart is a type of chart that displays the proportion of each category in a whole using slices of a circle. A pie chart can show how each category contributes to the total and compare the relative sizes of each category. However, in this case, there are two numerical variables involved, so a pie chart would not be able to show their relationship. A column chart is a type of chart that displays the comparison of one or more variables across categories using vertical bars. A column chart can show how each category differs from each other and rank them by size. However, in this case, a column chart would not be able to show the relationship between sales volume and average sales per customer, as it would only show one variable for each site.

Question #70

An analyst needs to conduct a quick analysis.

Which of the following is the FIRST step the analyst should perform with the data?

A . Conduct an exploratory analysis and use descriptive statistics.
B . Conduct a trend analysis and use a scatter chart.
C . Conduct a link analysis and illustrate the connection points.
D . Conduct an initial analysis and use a Pareto chart.

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