CompTIA CompTIA Certifications DA0-001 Questions & Answers

• Question 111:

  Which of the following differentiates a flat text file from other data types?

  A. Data is separated by a delimiter.

  B. Data is stored in defined rows.

  C. Data is defined with key-value pairs.

  D. Data is housed in a markup language.

  Correct Answer: A

  Explanation: A flat text file is a type of data file that contains only plain text without any formatting or markup. Data in a flat text file is usually separated by a delimiter, which is a character that marks the boundary between different fields or values. For example, a comma-separated values (CSV) file is a flat text file that uses commas as delimiters. Other common delimiters are tabs, spaces, semicolons, and pipes. Therefore, the correct answer is A. References: Plain text -Wikipedia, Comparison of document markup languages - Wikipedia

• Question 112:

  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

  Correct Answer: D

  Explanation: Stratified sampling is a data sampling method that involves dividing a population into subgroups by similar characteristics, such as age, gender, income, etc. Then, a simple random sample is drawn from each subgroup. This method ensures that each subgroup is adequately represented in the sample and reduces the sampling error. References: CompTIA Data+ Certification Exam Objectives, page 11.

• Question 113:

  A data analyst needs to present the results of an online marketing campaign to the marketing manager. The manager wants to see the most important KPIs and measure the return on marketing investment. Which of the following should the data analyst use to BEST communicate this information to the manager?

  A. A real-time monitor that allows the manager to view performance the day the campaign was launched

  B. A sell-service dashboard that allows the manager to look at the company's annual budget performance

  C. A spreadsheet of the raw data from all marketing campaigns and channels

  D. A summary with statistics, conclusions, and recommendations from the data analyst

  Correct Answer: D

  Explanation: A summary with statistics, conclusions, and recommendations from the data analyst is the best way to communicate the results of an online marketing campaign to the marketing manager. A summary can provide a concise and clear overview of the most important KPIs and measure the return on marketing investment, as well as highlight the main findings and insights from the data analysis. A summary can also include actionable suggestions and best practices for improving the campaign performance and achieving the marketing objectives. A summary is different from other options, such as a real-time monitor, a self-service dashboard, or a spreadsheet of raw data, which may not provide enough context, interpretation, or guidance for the manager. Therefore, the correct answer is D. References: How to Write a Data Analysis Report: 6 Essential Tips, How to Write a Marketing Report (with Pictures) - wikiHow

• Question 114:

  A site reliability team wants to monitor the stability of their website. so they can proactively diagnose issues when they occur Which of the following deliverables would best suit their needs?

  A. A self-serve dashboard of website performance that updates in real time

  B. A weekly log report of site visits and user actions

  C. A portal that is refreshed daily and reports errors classified by type

  D. A daily summary email indicating website outages for the previous day

  Correct Answer: A

  Explanation: The best deliverable that would suit the site reliability team's needs is A. A self-serve dashboard of website performance that updates in real time. A self-serve dashboard is a visual display of the most important information needed to achieve one or more objectives, consolidated and arranged on a single screen so the information can be monitored at a glance. A self-serve dashboard of website performance that updates in real time would allow the site reliability team to easily and quickly access the information they need about the stability of their website, such as uptime, response time, error rate, traffic volume, etc. A self-serve dashboard would also enable the team to proactively diagnose issues when they occur, by providing alerts, notifications, or drill-down options. A self-serve dashboard would also be more interactive and engaging than a report or an email. A weekly log report of site visits and user actions would not be a good deliverable for the site reliability team's needs, because it would not provide timely or relevant information about the stability of their website. A weekly log report would be too infrequent and delayed to monitor and diagnose issues when they occur. A weekly log report would also focus on the behavior and actions of the users, rather than the performance and functionality of the website. A portal that is refreshed daily and reports errors classified by type would not be a good deliverable for the site reliability team's needs, because it would not provide real-time or comprehensive information about the stability of their website. A portal that is refreshed daily would be too slow and outdated to monitor and diagnose issues when they occur. A portal that reports errors classified by type would be too narrow and limited to capture the full picture of the website performance. A daily summary email indicating website outages for the previous day would not be a good deliverable for the site reliability team's needs, because it would not provide real-time or actionable information about the stability of their website. A daily summary email would be too late and retrospective to monitor and diagnose issues when they occur. A daily summary email indicating website outages would also be too passive and generic to help the team resolve or prevent issues in the future.

• Question 115:

  

  Which of the following summary statements upholds integrity in data reporting?

  A. Sales are approximately equal for Product A and Product B across all strategies.

  B. Strategy 4 provides the best sales in comparison to other strategies.

  C. While Strategy 2 does not result in the highest sales of Product D. over all products it appears to be the most effective.

  D. Product D should be promoted more than the other products in all strategies.

  Correct Answer: C

  Answer: C. While Strategy 2 does not result in the highest sales of Product D. over all products it appears to be the most effective. A summary statement that upholds integrity in data reporting should be accurate, unbiased, and supported by evidence. Option C is the only statement that meets these criteria, as it reflects the data shown in the bar graph without exaggerating or distorting it. Option C also acknowledges the limitation of the statement by using the word "appears", which indicates that there may be other factors or variables that affect the sales performance. Option A is inaccurate, as sales are not approximately equal for Product A and Product B across all strategies. Product A has higher sales than Product B in strategies 1, 3, and 5, while Product B has higher sales than Product A in strategies 2 and 4. Option B is biased, as it does not consider the sales of different products in each strategy. Strategy 4 provides the best sales for Product B, but not for the other products. Strategy 5 has the highest total sales across all products, as shown by the black line graph. Option D is unsupported by evidence, as it does not explain why Product D should be promoted more than the other products in all strategies. Product D has the lowest sales among all products in strategies 1, 3, and 4, and only slightly higher sales than Product C in strategies 2 and 5.

• Question 116:

  Which of the following data cleansing issues will be fixed when a DISTINCT function is applied?

  A. Missing data

  B. Duplicate data

  C. Redundant data

  D. Invalid data

  Correct Answer: B

  Explanation: This is because duplicate data refers to data that is repeated or copied in a data set, which can affect the quality and validity of the analysis. A DISTINCT function is a type of function that removes duplicate values from a column or a table, leaving only unique values. For example, a DISTINCT function in SQL that can achieve this is:

  

  The other data cleansing issues will not be fixed by applying a DISTINCT function. Here is why:

  Missing data refers to data that is absent or incomplete in a data set, which can affect the accuracy and reliability of the analysis. A DISTINCT function does not help with missing data, because it does not fill in or impute the missing values. Redundant data refers to data that is unnecessary or irrelevant for the analysis, which can affect the efficiency and performance of the analysis. A DISTINCT function does not help with redundant data, because it does not remove or filter out the redundant values. Invalid data refers to data that is incorrect or inaccurate in a data set, which can affect the validity and reliability of the analysis. A DISTINCT function does not help with invalid data, because it does not validate or correct the invalid values.

• Question 117:

  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

  Correct Answer: C

  Explanation: Parsing is the data manipulation technique that should be used to separate the column into multiple columns for each component of the name. Parsing is the process of breaking down a string of text into smaller units, such as words, symbols, or numbers. Parsing can be used to extract specific information from a text column, such as names, addresses, phone numbers, etc. Parsing can also be used to split a text column into multiple columns based on a delimiter, such as a comma, space, or dash1. In this case, the analyst can use parsing to split the column by the comma delimiter and create three new columns: one for the last name, one for the first name, and one for the middle initial. This will make the data more organized and easier to analyze.

• Question 118:

  Given the following customer and order tables:

  Which of the following describes the number of rows and columns of data that would be present after performing an INNER JOIN of the tables?

  A. Five rows, eight columns

  B. Seven rows, eight columns

  C. Eight rows, seven columns

  D. Nine rows, five columns

  Correct Answer: B

  Explanation: This is because an INNER JOIN is a type of join that combines two tables based on a matching condition and returns only the rows that satisfy the condition. An INNER JOIN can be used to merge data from different tables that have a common column or a key, such as customer ID or order ID. To perform an INNER JOIN of the customer and order tables, we can use the following SQL statement:

  

  This statement will select all the columns (*) from both tables and join them on the customer ID column, which is the common column between them. The result of this statement will be a new table that has seven rows and eight columns, as shown below:

  

  The reason why there are seven rows and eight columns in the result table is because:

  There are seven rows because there are six customers and six orders in the original tables, but only five customers have matching orders based on the customer ID column. Therefore, only five rows will have data from both tables, while one

  row will have data only from the customer table (customer 5), and one row will have no data at all (null values).

  There are eight columns because there are four columns in each of the original tables, and all of them are selected and joined in the result table. Therefore, the result table will have four columns from the customer table (customer ID, first

  name, last name, and email) and four columns from the order table (order ID, order date, product, and quantity).

• Question 119:

  A data analyst needs to calculate the mean for Q1 sales using the data set below:

  

  Which of the following is the mean?

  A. $2,466.18

  B. $2,667.60

  C. $3,082.72

  D. $12,330.88

  Correct Answer: C

  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 References: CompTIA Data+ Certification Exam Objectives, page 9

• Question 120:

  Alex wants to use data from his corporate sale, CRM, and shipping systems to try and predict future sales.

  Which of the following systems is the most appropriate?

  Choose the best answer.

  A. Data mart.

  B. OLAP.

  C. Data Warehouse.

  D. OLTP.

  Correct Answer: C