CompTIA CompTIA Certifications DA0-001 Questions & Answers

• Question 131:

  Which of the following should be accomplished NEXT after understanding a business requirement for a data analysis report?

  A. Rephrase the business requirement.

  B. Determine the data necessary for the analysis.

  C. Build a mock dashboard/presentation layout.

  D. Perform exploratory data analysis.

  Correct Answer: B

  Explanation: Exploratory data analysis (EDA) is a process of examining and summarizing a dataset using various techniques, such as descriptive statistics, visualizations, correlations, outliers detection, and hypothesis testing. EDA can help

  reveal the main characteristics, patterns, trends, and insights from the data, as well as identify any problems or issues with the data quality or structure. EDA is usually performed after understanding a business requirement for a data analysis

  report and before building a mock dashboard/presentation layout. Therefore, the correct answer is B. References:

  [What is Exploratory Data Analysis? | Definition and Examples], [Exploratory Data Analysis in Python]

• Question 132:

  Which of the following is a control measure for preventing a data breach?

  A. Data transmission

  B. Data attribution

  C. Data retention

  D. Data encryption

  Correct Answer: D

  Explanation: This is because data encryption is a type of control measure that prevents a data breach, which is an unauthorized or illegal access or use of data by an external or internal party. Data encryption can prevent a data breach by protecting and securing the data using a code or a key that scrambles or transforms the data into an unreadable or incomprehensible format, which can only be decoded or restored by authorized users who have the correct code or key. For example, data encryption can prevent a data breach by encrypting the data in transit or at rest, such as when the data is sent over a network or stored in a device. The other control measures are not used for preventing a data breach. Here is why:

  Data transmission is a type of process that transfers and exchanges data between different sources or systems, such as databases, cloud services, or web applications. Data transmission does not prevent a data breach, but rather exposes the data to potential risks or threats during the transfer or exchange. However, data transmission can be made more secure and less vulnerable to a data breach by using encryption or other methods, such as authentication or authorization. Data attribution is a type of feature or function that assigns and tracks the ownership and origin of the data, such as the creator, modifier, or source of the data. Data attribution does not prevent a data breach but rather provides information and evidence about the data provenance and history. However, data attribution can be useful for detecting and responding to a data breach by using audit logs or metadata to identify and trace any unauthorized or illegal access or use of the data. Data retention is a type of policy or standard that specifies and regulates the storage and preservation of the data, such as the duration, location, or format of the data. Data retention does not prevent a data breach, but rather affects the availability and accessibility of the data for future use or reference. However, data retention can be optimized and aligned with the legal and ethical requirements and standards of the industry or the organization to reduce the risk or impact of a data breach.

• Question 133:

  A sales team wants visibility of current sales numbers, pipeline, and team performance. The team would also like to see calculations of individuals' earned commissions and projected commissions based on sales, but they want that information to be kept confidential. Which of the following would be the BEST way to provide this visibility?

  A. Create a dashboard displaying a data refresh date so users know the current sales numbers and configure permissions to control access.

  B. Create a dashboard for sales numbers, pipeline, and team and individual performance for the management team.

  C. Create a dashboard with filters for the overall team, individuals, and management. Users can filter to see the data they want.

  D. Create a dashboard with views for team, individuals, and management. Configure permissions to control access.

  Correct Answer: D

  Create a dashboard with views for team, individuals, and management. Configure permissions to control access. This is because a dashboard is a type of visualization that displays multiple charts or graphs on a single page, usually to provide

  an overview or summary of some data or information. A dashboard can be used to provide visibility of current sales numbers, pipeline, and team performance by showing different metrics and indicators related to these aspects. By creating a

  dashboard with views for team, individuals, and management, the analyst can customize the content and layout of the dashboard for different audiences and purposes. By configuring permissions to control access, the analyst can ensure that

  the confidential information, such as individuals' earned commissions and projected commissions based on sales, is only visible to the authorized users. The other ways are not the best way to provide this visibility. Here is why:

  Creating a dashboard displaying a data refresh date so users know the current sales numbers and configuring permissions to control access would not be sufficient to provide visibility of pipeline and team performance, as well as individuals'

  earned commissions and projected commissions based on sales. The dashboard would only show the current sales numbers and the date when the data was updated, which would not give a comprehensive or detailed view of the sales

  situation.

  Creating a dashboard for sales numbers, pipeline, and team and individual performance for the management team would not be appropriate to provide visibility for the sales team, as they would not have access to the dashboard or the

  information they need. The dashboard would only be available for the management team, which would limit the transparency and collaboration among the sales team members.

  Creating a dashboard with filters for the overall team, individuals, and management would not be secure to provide visibility of confidential information, such as individuals' earned commissions and projected commissions based on sales. The

  dashboard would allow users to filter and see the data they want, which could expose sensitive or personal information to unauthorized users.

• Question 134:

  Jhon is working on an ELT process that sources data from six different source systems.

  Looking at the source data, he finds that data about the sample people exists in two of six systems.

  What does he have to make sure he checks for in his ELT process?

  Choose the best answer.

  A. Duplicate Data.

  B. Redundant Data.

  C. Invalid Data.

  D. Missing Data.

  Correct Answer: C

  Duplicate Data.

  While invalid, redundant, or missing data are all valid concerns, data about people exists in two of the six systems. As such, Jhon needs to account for duplicate data issues.

• Question 135:

  Which of the following are reasons to conduct data cleansing? (Select two).

  A. To perform web scraping

  B. To track KPls

  C. To improve accuracy

  D. To review data sets

  E. To increase the sample size

  F. To calculate trends

  Correct Answer: CF

  Two reasons to conduct data cleansing are: To improve accuracy: Data cleansing helps to ensure that the data is correct, consistent, and reliable. This can improve the quality and validity of the analysis, as well as the decision-making and outcomes based on the data12 To calculate trends: Data cleansing helps to remove or resolve any errors, outliers, or missing values that could distort or skew the data. This can help to identify and measure the patterns, changes, or relationships in the data over time13

• Question 136:

  Five dogs have the following heights in millimeters:

  300, 430, 170, 470, 600

  Which of the following is the mean height for the five dogs?

  A. 394mm

  B. 405mm

  C. 493mm

  D. 504mm

  Correct Answer: A

  The mean height for the five dogs is calculated by adding up all the heights and dividing by the number of dogs. The formula is:

  mean = (300 + 430 + 170 + 470 + 600) / 5 mean = 1970 / 5 mean = 394

  Therefore, option A is correct.

  Option B is incorrect because it is the median height, which is the middle value when the heights are arranged in ascending order.

  Option C is incorrect because it is the mean height multiplied by 1.25.

  Option D is incorrect because it is the mean height multiplied by 1.28.

• Question 137:

  Emma is working in a data warehouse and finds a finance fact table links to an organization dimension, which in turn links to a currency dimension that not linked to the fact table.

  What type of design pattern is the data warehouse using?

  A. Star.

  B. Sun.

  C. Snowflake.

  D. Comet.

  Correct Answer: C

  Correct answer C. Snowflake.

  Since the dimension links to a dimension that isn't connected to the fact table, it must be a Snowflake, with a Star, all dimensions link directly to the fact table, Sun and Comet are not data warehouse design patterns.

• Question 138:

  A data analyst is asked to create a sales report for the second-quarter 2020 board meeting, which will include a review of the business's performance through the second quarter. The board meeting will be held on July 15, 2020, after the numbers are finalized. Which of the following report types should the data analyst create?

  A. Static

  B. Real-time

  C. Self-service

  D. Dynamic

  Correct Answer: A

  Explanation: A dynamic report is a type of report that shows data that changes or updates automatically based on certain criteria or parameters. A dynamic report can allow users to interact with the data, filter it, drill down into it, or visualize it in different ways. A dynamic report is suitable for situations where the data changes frequently or where real-time or near-real-time data is needed for decision making or analysis. In this case, the data analyst is asked to create a sales report for the second-quarter 2020 board meeting, which will include a review of the business's performance through the second quarter. The board meeting will be held on July 15, 2020, after the numbers are finalized. This means that the data analyst does not need to show real-time or dynamic data, but rather a fixed and accurate view of the sales data for the second quarter. Therefore, a static report would be the best way to meet this stakeholder requirement. Therefore, the correct answer is A. References: [What are Dynamic Reports? | Sisense], Static vs Dynamic Reports - What's The Difference? | datapine

• Question 139:

  An e-commerce company recently tested a new website layout. The website was tested by a test group of customers, and an old website was presented to a control group. The table below shows the percentage of users in each group who made purchases on the websites: Which of the following conclusions is accurate at a 95% confidence interval?

  

  A. In Germany, the increase in conversion from the new layout was not significant.

  B. In France, the increase in conversion from the new layout was not significant.

  C. In general, users who visit the new website are more likely to make a purchase.

  D. The new layout has the lowest conversion rates in the United Kingdom.

  Correct Answer: A

  Explanation: The p-value is a measure of how likely it is to observe a difference in conversion rates as large or larger than the one observed, assuming that there is no difference between the groups. A common threshold for statistical significance is 0.05, meaning that there is a 5% or less chance of observing such a difference by chance alone. The table shows the p-values for each country, and we can see that only Germany has a p- value above 0.05 (0.13). This means that we cannot reject the null hypothesis that there is no difference in conversion rates between the test and control groups in Germany. Therefore, the increase in conversion from the new layout was not significant in Germany. For the other countries, the p-values are below 0.05, indicating that the increase in conversion from the new layout was statistically significant. Option A is correct. Option B is incorrect because the increase in conversion from the new layout was significant in France (p-value = 0.002). Option C is incorrect because it does not account for the variation across countries. While the overall conversion rate for the test group (8.4%) is higher than the control group (6.8%), this difference may not be statistically significant when we consider the country-specific effects. Option D is incorrect because the new layout has the highest conversion rate in the United Kingdom (9.6%), not the lowest. References: P-value Calculator and Statistical Significance Calculator p-value Calculator | Formula | Interpretation How to obtain the P value from a confidence interval | The BMJ Confidence Intervals and P-values for Percent Change / Relative Difference

• Question 140:

  A data analyst wants to create "Income Categories" that would be calculated based on the existing variable "Income". The "Income Categories" would be as follows:

  Income category 1: less than $1.

  Income category 2: more than $1 and less than $20,000.

  Income category 3: more than $20,001 and less than $40,000.

  Income category 4: more than $40,001.

  Which of the following data manipulation techniques should the data analyst use to create "Income Categories"?

  A. Data merge

  B. Derived variables

  C. Data blending

  D. Data append

  Correct Answer: B

  The correct answer is B: Derived variables Derived variables are variables that you create by calculating or categorizing variables that already exist in your data set. Data merge is incorrect. Data merging is the process of combining two or

  more data sets into a single data set. Data blending is incorrect. Data blending involves pulling data from different sources and creating a single, unique, dataset for visualization and analysis.

  Data append is incorrect. A data append is a process that involves adding new data elements to an existing database.