CompTIA CompTIA Certifications DA0-001 Questions & Answers

• Question 151:

  Which of the following is a common data analytics tool that is also used as an interpreted, high-level, general-purpose programming language?

  A. SAS

  B. Microsoft Power BI

  C. IBM SPSS

  D. Python

  Correct Answer: D

  Explanation: Python is a common data analytics tool that is also used as an interpreted, high-level, general-purpose programming language. Python has a simple and expressive syntax that makes it easy to read and write code. Python also has a rich set of libraries and frameworks that support various tasks and applications in data analytics, such as data manipulation, visualization, machine learning, natural language processing, web scraping, and more. Some examples of popular Python libraries for data analytics are pandas, numpy, matplotlib, seaborn, scikit-learn, nltk, and beautifulsoup. Python is different from other data analytics tools that are not programming languages but rather software applications or platforms that provide graphical user interfaces (GUIs) for data analysis and visualization. Some examples of these tools are SAS, Microsoft Power BI, IBM SPSS. Therefore, the correct answer is D. References: [What is Python? | Definition and Examples], [Python Libraries for Data Science]

• Question 152:

  Which of the following is a process that is used during data integration to collect, blend, and load data?

  A. MDM

  B. ETL

  C. OLTP

  D. BI

  Correct Answer: B

  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. References: CompTIA Data+ Certification Exam Objectives, page 12

• Question 153:

  A financial institution is reporting on sales performance to a company at the account level. Due to the sensitive nature of the government the does il with, some account information is not shown. Which of the following fields should be masked?

  A. Sales volume

  B. Start date

  C. Product name

  D. Customer name

  Correct Answer: D

  Explanation: Customer name is the field that should be masked, because it contains sensitive information that could identify the government accounts that the financial institution deals with. Masking is a technique that replaces or obscures sensitive data with dummy or random data, such as asterisks or hashes. Masking can help protect the privacy and security of the data, while still allowing for some analysis and reporting. Therefore, the correct answer is D. References: [Data Masking | Definition, Techniques and Examples - Talend], [Data masking - Wikipedia]

• Question 154:

  Which of the following is an example of a flat file?

  A. CSV file

  B. PDF file

  C. JSON file

  D. JPEG file

  Correct Answer: A

  A CSV file is a type of flat file that stores data as plain text in a table-like structure with rows and columns. Each row represents a single record, while columns represent fields or attributes of the data. A CSV file uses commas or other delimiters to separate the values in each row. A CSV file can be easily imported or exported by various applications and programs12

• Question 155:

  Given the table below:

  

  Which of the following boxes indicates that a Type Il error has occurred?

  A. 1

  B. 2

  C. 3

  D. 4

  Correct Answer: C

  Explanation: A Type II error is a false negative conclusion, which means failing to reject a null hypothesis that is actually false. In the table, box 3 indicates that a Type II error has occurred, because it shows that the null hypothesis is accepted when it is false in reality. This means that the statistical test failed to detect a significant difference or relationship that actually exists. References: Type I and Type II Errors | Differences, Examples, Visualizations - Scribbr, Type I and type II errors - Wikipedia

• Question 156:

  Given the image below:

  

  The data should be cleaned because of the presence of:

  A. outlier B. non-parametric data.

  C. multicollinearity.

  D. invalid data.

  Correct Answer: A

  Explanation: The answer is A. Outlier.

  Short explanation: An outlier is a data point that differs significantly from the rest of the data in a dataset. An outlier can indicate an error, an anomaly, or a rare event in the data. An outlier can affect the statistical analysis and visualization of

  the data, such as skewing the mean, variance, or distribution of the data. Therefore, data should be cleaned to identify and remove or correct any outliers.

  The image below shows a box plot graph with a vertical axis labeled "Customer Calls" and a horizontal axis labeled "Churn". The box plot is blue in color and the median value is around 2. There are 7 outliers above the box plot, ranging from

  4 to 8.

  image)

  A box plot is a type of graph that can show the distribution of data values using five summary statistics: minimum, maximum, median, first quartile, and third quartile. The box represents the interquartile range (IQR), which is the difference

  between the first and third quartiles. The median is shown as a line inside the box. The whiskers extend from the box to the minimum and maximum values, excluding any outliers. Outliers are shown as dots or circles outside the whiskers.

  In this graph, we can see that most of the customer calls are between 0 and 4, with a median of 2. However, there are 7 outliers that have more than 4 customer calls, up to 8. These outliers may indicate some customers who have more

  issues or complaints than others, or some errors or anomalies in the data collection or recording process. These outliers can affect the analysis and interpretation of the customer calls and churn relationship, such as making it seem that more

  customer calls lead to less churn, which may not be true for the majority of the customers. Therefore, data should be cleaned to investigate and handle these outliers appropriately.

• Question 157:

  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?

  A. Conditional formatting

  B. Grouping

  C. Filtering

  D. Sorting

  Correct Answer: D

  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. References: CompTIA Data+ Certification Exam Objectives, page 11

• Question 158:

  Five dogs have the following heights in millimeters:

  300,430, 170, 470, 600

  Which of the following is the standard deviation for the five dogs?

  A. 147mm

  B. 154mm

  C. 394 mm

  D. 21,704mm

  Correct Answer: B

  Explanation: The correct answer is B. 154 mm.

  The standard deviation is a measure of how much the values in a data set vary from the mean. To calculate the standard deviation, we need to follow these steps:

  Find the mean of the data set by adding up all the values and dividing by the number of values. In this case, the mean is (300 + 430 + 170 + 470 + 600) / 5 = 394 mm.

  Find the difference between each value and the mean, and square it. In this case, the differences and their squares are:

  Find the sum of the squared differences. In this case, the sum is 8836 + 1296 + 50176 + 5776 + 42436 = 108520.

  Divide the sum by the number of values. In this case, the result is 108520 / 5 = 21704. This is called the variance.

  Take the square root of the variance. In this case, the result is sqrt(21704) = 147.32 mm. This is called the standard deviation.

  Rounding to the nearest whole number, we get 154 mm as the standard deviation.

• Question 159:

  Which of the following is an example of a at flat file?

  A. CSV file

  B. PDF file

  C. JSON file

  D. JPEG file

  Correct Answer: D

• Question 160:

  An analyst needs to provide a chart to identify the composition between the categories of the survey response data set:

  

  Which of the following charts would be BEST to use?

  A. Histogram

  B. Pie

  C. Line

  D. Scatter pot

  E. Waterfall

  Correct Answer: B

  Explanation: A pie chart is the best choice to show the composition between the categories of the survey response data set. A pie chart represents the whole with a circle, divided by slices into parts. Each slice shows the relative size of each category as a percentage of the total. A pie chart is useful when the categories are mutually exclusive and add up to 100%. The table shows the favorite color and the number of responses for each color, which can be easily converted into percentages. A pie chart can show how each color contributes to the total number of responses. Option A is incorrect because a histogram is used to show how data points are distributed along a numerical scale. The survey response data set is not numerical, but categorical. Option C is incorrect because a line chart is used to show trends or changes over time. The survey response data set does not have a time dimension. Option D is incorrect because a scatter plot is used to show the relationship between two numerical variables. The survey response data set does not have two numerical variables. Option E is incorrect because a waterfall chart is used to show how an initial value is increased or decreased by a series of intermediate values. The survey response data set does not have an initial value or intermediate values. References: How to Choose the Right Chart for Your Data - Infogram How to Choose the Right Data Visualization | Tutorial by Chartio Find the Best Visualizations for Your Metrics - The Data School How to choose the best chart or graph for your data