CompTIA DA0-001 Practice Test - Questions Answers
List of questions
Question 1
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Refer to the exhibit.
A data analyst needs to calculate the mean for Q1 sales using the data set below:
Which of the following is the mean?
Explanation:
The mean is the average of all the values in a data set. To calculate the mean, we add up all the values and divide by the number of values. In this case, the mean for Q1 sales is ($2,000 + $3,000 + $4,000 + $2,500 + $3,500) / 5 = $3,082.72 Reference: CompTIA Data+ Certification Exam Objectives, page 9
Question 2
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A data analyst is creating a report that will provide information about various regions, products, and time periods. Which of the following formats would be the MOST efficient way to deliver this report?
Explanation:
A dashboard with filters at the top that the user can toggle would be the most efficient way to deliver this report, because it allows the user to customize the view and explore different combinations of regions, products, and time periods. A workbook with multiple tabs for each region would be cumbersome and repetitive. A daily email with snapshots of regional summaries would not provide enough detail or interactivity. A static report with a different page for every filtered view would be too long and hard to navigate. Reference: CompTIA Data+ Certification Exam Objectives, page 14
Question 3
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Refer to the exhibit.
A customer list from a financial services company is shown below:
A data analyst wants to create a likely-to-buy score on a scale from 0 to 100, based on an average of the three numerical variables: number of credit cards, age, and income. Which of the following should the analyst do to the variables to ensure they all have the same weight in the score calculation?
Explanation:
Normalizing the variables means scaling them to a common range, such as 0 to 1 or -1 to 1, so that they have the same weight in the score calculation. Recoding the variables means changing their values or categories, which would alter their meaning and distribution. Calculating the percentiles of the variables means ranking them relative to each other, which would not account for their actual magnitudes. Calculating the standard deviations of the variables means measuring their variability, which would not make them comparable. Reference: CompTIA Data+ Certification Exam Objectives, page 10
Question 4
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Which of the following actions should be taken when transmitting data to mitigate the chance of a data leak occurring? (Choose two.)
Explanation:
Data encryption and data masking are two actions that can be taken when transmitting data to mitigate the chance of a data leak occurring. Data encryption means transforming data into an unreadable format that can only be decrypted with a key. Data masking means hiding or replacing sensitive data with fictitious or anonymized data. Both methods protect the confidentiality and integrity of the data in transit. Reference: CompTIA Data+ Certification Exam Objectives, page 13
Question 5
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A data analyst has been asked to organize the table below in the following ways:
By sales from high to low -By state in alphabetic order -
Which of the following functions will allow the data analyst to organize the table in this manner?
Explanation:
Sorting is the function that will allow the data analyst to organize the table in the desired manner. Sorting means arranging the data in a specific order, such as ascending or descending, based on one or more criteria. Sorting can be applied to any column in the table, such as sales or state. Reference:
CompTIA Data+ Certification Exam Objectives, page 11
Question 6
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Which of the following BEST describes the issue in which character values are mixed with integer values in a data set column?
Explanation:
The invalid data type is the best description for the issue in which character values are mixed with integer values in a data set column. Invalid data type means that the data does not match the expected or required format or structure for a given variable or attribute. For example, if a column is supposed to store numerical values, but some rows contain text values, then those rows have an invalid data type. Reference: CompTIA Data+ Certification Exam Objectives, page 10
Question 7
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Which of the following is a process that is used during data integration to collect, blend, and load data?
Explanation:
ETL is a process that is used during data integration to collect, blend, and load data. ETL stands for extract, transform, and load, which are the three main steps involved in moving data from different sources to a common destination, such as a data warehouse or a data lake. ETL helps to consolidate and standardize data for analysis and reporting purposes. Reference: CompTIA Data+ Certification Exam Objectives, page 12
Question 8
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An analyst has received the requirements for an internal user dashboard. The analyst confirms the data sources and then creates a wireframe. Which of the following is the NEXT step the analyst should take in the dashboard creation process?
Explanation:
Getting stakeholder approval is the next step the analyst should take in the dashboard creation process, after confirming the data sources and creating a wireframe. Stakeholder approval means getting feedback and validation from the intended users or clients of the dashboard, to ensure that it meets their expectations and requirements. This step helps to avoid rework and ensure customer satisfaction. Reference: CompTIA Data+ Certification Exam Objectives, page 14
Question 9
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A data analyst has been asked to derive a new variable labeled "Promotion_flag" based on the total quantity sold by each salesperson. Given the table below:
Which of the following functions would the analyst consider appropriate to flag "Yes" for every salesperson who has a number above 1,000,000 in the Quantity_sold column?
Explanation:
A logical function is a type of function that returns a value based on a condition or a set of conditions. For example, the IF function in Excel can be used to check if a certain condition is met, and then return one value if true, and another value if false. In this case, the data analyst can use a logical function to check if the Quantity_sold column is greater than 1,000,000, and then return "Yes" if true, and "No" if false. This would create a new variable called Promotion_flag that indicates whether the salesperson has sold more than 1,000,000 units or not. Reference: CompTIA Data+ Certification Exam Objectives, Logical functions (reference)
Question 10
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Refer to the exhibit.
Given the diagram below:
Which of the following data schemas shown?
Explanation:
A relational database is a type of database that organizes data into tables, where each table has a fixed number of columns and a variable number of rows. Each row in a table represents a record or an entity, and each column represents an attribute or a property of that entity. The tables are linked by common fields, called keys, which enable the database to establish relationships between the data. A relational database schema is a diagram that shows the structure and organization of the tables, columns, keys, and constraints in a relational database. The diagram given in the question is an example of a relational database schema, as it shows two tables: "Runs" and "Experiments", with their respective columns, data types, and primary keys. The "Runs" table also has a foreign key that references the "ExperimentId" column in the "Experiments" table, indicating a relationship between the two tables. Therefore, the correct answer is D. Reference: What is a database schema? | IBM, Database Schema - Javatpoint
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