CompTIA DA0-001 Online Practice Questions and Exam Preparation

CompTIA DA0-001 Online Questions & Answers

• Question 121:

  An analyst needs to create an analytics dashboard for an employee intranet site to improve the search functionality, display relevant information, and maintain an updated FAQ page.

  Which of the following visualizations would best represent what employees are searching for?

  A. A word cloud
  B. A histogram
  C. A pie chart
  D. A scatter plot
  A. A word cloud

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  Explanation

  A word cloud is an ideal choice for visualizing what employees are searching for on an intranet site. It represents the frequency of word occurrence in a visually impactful way, with more commonly searched terms appearing larger in the cloud. This allows for quick identification of the most popular queries and topics of interest among employees. Unlike histograms, pie charts, or scatter plots, word clouds can effectively display textual data, which is the nature of search queries. They are particularly useful for analyzing text data from surveys or feedback forms, which can be similar to search query data in an intranet environment.

  References:

  1: "What Are Word Clouds? Pros and Cons of Word Cloud Visualizations" - Alida

  2: "Using Word Clouds for Powerful Data Visualization" - WordCloud.app blog

  3: "Ultimate Google Data Studio Word Cloud Guide: Visualization 2024" - At Once

  4: "How to Create Word Cloud in Power BI" - Zebra BI

• Question 122:

  Which one of the following values will appear first if they are sorted in descending order?

  A. Aaron.
  B. Molly.
  C. Xavier.
  D. Adam.
  C. Xavier.

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  Explanation

  The value that will appear first if they are sorted in descending order is Xavier. Descending order means arranging values from the largest to the smallest, or from the last to the first in alphabetical order. In this case, Xavier is the last name in

  alphabetical order, so it will appear first when sorted in descending order. The other names will appear in the following order: Molly, Adam, Aaron.

  Sorting Data - W3Schools

• Question 123:

  Mario works with a group of R programmers tasked with copying data from an accounting system into a data warehouse.

  In what phase are the group's R skills most relevant?

  A. Extract.
  B. Load.
  C. Transform.
  D. Purge.
  C. Transform.

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  Explanation

• Question 124:

  Which of the following is a characteristic of a relational database?

  A. It utilizes key-value pairs.
  B. It has undefined fields.
  C. It is structured in nature.
  D. It uses minimal memory.
  C. It is structured in nature.

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  Explanation

  It is structured in nature. This is because a relational database is a type of database that organizes data into tables, which consist of rows and columns. A relational database is structured in nature, which means that the data has a predefined schema or format, and follows certain rules and constraints, such as primary keys, foreign keys, or referential integrity. A relational database can be used to store, query, and manipulate data using a structured query language (SQL). The other characteristics are not true for a relational database. Here is why:

  It utilizes key-value pairs. This is not true for a relational database, because key-value pairs are a way of storing data that associates each value with a unique key, such as an identifier or a name. Key-value pairs are typically used in non-relational databases, such as NoSQL databases, which do not have tables, rows, or columns, but rather store data in various formats, such as documents, graphs, or columns. It has undefined fields. This is not true for a relational database, because fields are another name for columns in a table, which define the attributes or properties of each row or record in the table. Fields have defined names, types, and lengths in a relational database, which specify the format and size of the data that can be stored in each field. It uses minimal memory. This is not true for a relational database, because memory is the amount of space or storage that is used by a database to store and process data. Memory usage depends on various factors, such as the size, complexity, and number of tables and queries in a relational database. A relational database can use a lot of memory if it has many tables with many rows and columns, or if it performs complex or frequent queries on the data.

• Question 125:

  A business unit made the following modification to the values in a table:

  

  Which of the following data quality dimensions was applied in this scenario?

  A. Integrity
  B. Consistency
  C. Completeness
  D. Accuracy
  D. Accuracy

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  Explanation

• Question 126:

  A data analyst is asked on the morning of April 9, 2020, to create a sales report that identifies sales year to date. The daily sales data is current through the end of the day.

  Which of the following date ranges should be on the report?

  A. January 1, 2020 to April 1, 2020
  B. January 1, 2020 to April 7, 2020
  C. January 1, 2020 to April 8, 2020
  D. January 1, 2020 to April 9, 2020
  D. January 1, 2020 to April 9, 2020

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  Explanation

  This is because sales year to date refers to the sales that have occurred from the beginning of the current year until the current date. By creating a sales report that identifies sales year to date, the analyst can measure and compare the sales performance and progress of the current year. Since the analyst is asked to create the sales report on the morning of April 9, 2020, and the daily sales data is current through the end of the day, the date range that should be on the report is January 1, 2020 to April 9, 2020. The other date ranges are not correct for identifying sales year to date. Here is why:

  January 1, 2020 to April 1, 2020 would not include the sales that occurred in the first eight days of April, which would underestimate the sales year to date. January 1, 2020 to April 7, 2020 would not include the sales that occurred in the last two days of April, which would also underestimate the sales year to date. January 1, 2020 to April 8, 2020 would not include the sales that occurred on April 9, which would also underestimate the sales year to date.

• Question 127:

  A data architect is designing a data solution for a retail clothing store chain. Each store has a database that tracks sales transactions. The data architect needs to create a summary table that will be used for a senior executive dashboard. The summary table should not contain duplicate store information. Which of the following should the data architect create?

  A. A check constraint
  B. A primary key
  C. A foreign key
  D. A unique constraint
  D. A unique constraint

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  Explanation

• Question 128:

  An analyst is reviewing the following data:

  Car IDSpeed

  123155

  566436

  564418

  650567

  546436

  645638

  Which of the following should the analyst include in the measures of central tendency for speed?

  A. Mode = 38 Range = 31 Mean = 42.5
  B. Range = 49 Max = 67 Min = 18
  C. Mode = 36 Max = 67 Min = 18
  D. Mode = 36 Median = 37 Mean = 41.5
  D. Mode = 36 Median = 37 Mean = 41.5

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  Explanation

  The measures of central tendency include the mode, median, and mean. The mode is the value that appears most frequently in a data set. In this case, the speed of 36 appears twice, making it the mode. The median is the middle value when

  a data set is ordered from least to greatest; for these speeds, when ordered (18, 36, 36, 38, 55, 67), the median is the average of the two middle numbers, which is ( \frac{36 + 38}{2} = 37 ). The mean is the average of all values, calculated as

  ( \frac{55 + 36 + 18 + 67 + 36 + 38}{6} = 41.7 ).

  References:

  The calculation of the mode, median, and mean is based on standard statistical formulas and definitions.

  The measures of central tendency for speed include the mode, median, and mean. To calculate these, we first need to organize the data:

  Speeds in ascending order: 18, 36, 36, 38, 55, 67

  Mode is the value that appears most frequently, which is 36, as it appears twice. Median is the middle value when the data is ordered. Since we have an even number of observations, we take the average of the two middle values (36 and

  38), resulting in 37. Mean is the sum of all values divided by the number of values. (18+36+36+38+55+67)/6=41.5(18+36+36+38+55+67)/6=41.5. Thus, the correct option is D, which includes Mode = 36, Median = 37, and Mean = 41.5. The range, maximum, and

  minimum values, although useful in understanding data dispersion, are not measures of central tendency and are therefore not relevant to this specific question.

• Question 129:

  Which of the following concepts should be applied if a data set with 40 fields needs to be pared down to 20 fields and contains similar data across multiple fields?

  A. Duplication
  B. Consolidation
  C. Compliance
  D. Standardization
  B. Consolidation

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  Explanation

  Consolidation is the process of combining multiple elements into a single, more effective or coherent whole. In the context of data analytics, consolidation would involve merging similar fields to reduce the overall number of fields in a dataset.

  This is particularly useful when a dataset contains redundant or similar data across multiple fields, as it helps to simplify the data structure and improve efficiency. Techniques such as dimensionality reduction are often applied to achieve this,

  where the goal is to retain the most informative and representative features of the data while reducing the number of total features.

  References:

  Applied Dimensionality Reduction -- 3 Techniques using Python.

  Seven Techniques for Data Dimensionality Reduction.

  Best practices when working with datasets.

  Effectively Handling Large Datasets.

• Question 130:

  Which of the following types of analyses should be used to evaluate the connections and anomalies in a data set when either known patterns are being violated or new patterns are emerging?

  A. Correlation
  B. Descriptive
  C. Graph
  D. Regression
  C. Graph

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  Explanation