CompTIA CompTIA Certifications DA0-001 Questions & Answers

• Question 121:

  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?

  A. A workbook with multiple tabs for each region

  B. A daily email with snapshots of regional summaries

  C. A static report with a different page for every filtered view

  D. A dashboard with filters at the top that the user can toggle

  Correct Answer: D

  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. References: CompTIA Data+ Certification Exam Objectives, page 14

• Question 122:

  Which of the following descriptive statistical methods are measures of central tendency? (Choose two.)

  A. Mean

  B. Minimum

  C. Mode

  D. Variance

  E. Correlation

  F. Maximum

  Correct Answer: AC

  Explanation: Mean and mode are measures of central tendency, which describe the typical or most common value in a distribution of data. Mean is the arithmetic average of all the values in a dataset, calculated by adding up all the values and dividing by the number of values. Mode is the most frequently occurring value in a dataset. Other measures of central tendency include median, which is the middle value when the data is sorted in ascending or descending order.

• Question 123:

  Which of the following statistical methods requires two or more categorical variables?

  A. Simple linear regression

  B. Chi-squared test

  C. Z-test

  D. Two-sample t-test

  Correct Answer: B

  This is because a chi-squared test is a type of statistical method that tests the association or independence between two or more categorical variables, such as gender, race, or occupation. A chi-squared test can be used to compare the observed frequencies of the categories with the expected frequencies under the null hypothesis of no association or independence. For example, a chi-squared test can be used to determine if there is a relationship between smoking and lung cancer. The other statistical methods do not require two or more categorical variables. Here is why:

  Simple linear regression is a type of statistical method that models the relationship between a continuous dependent variable and a continuous or categorical independent variable, such as height, weight, or education level. A simple linear regression can be used to estimate the slope and intercept of the best-fitting line that describes how the dependent variable changes with the independent variable. For example, a simple linear regression can be used to predict the weight of a person based on their height. Z-test is a type of statistical method that tests the significance of the difference between a sample mean and a population mean, or between two sample means, when the population standard deviation or the sample sizes are large enough. A z-test can be used to compare the average scores of two groups of students on a standardized test. Two-sample t-test is a type of statistical method that tests the significance of the difference between two sample means when the population standard deviation is unknown or the sample sizes are small. A two-sample t-test can be used to compare the average salaries of two groups of employees in different departments.

• Question 124:

  The number of phone calls that the call center receives in a day is an example of:

  A. continuous data.

  B. categorical data.

  C. ordinal data.

  D. discrete data.

  Correct Answer: D

  Explanation: Discrete data is a type of data that can only take certain values, usually whole numbers or integers. Discrete data can be counted, but not measured. For example, the number of students in a class, the number of books in a library, or the number of phone calls that a call center receives in a day are all examples of discrete data. Discrete data is different from continuous data, which can take any value within a range, and can be measured with precision. For example, the height of a person, the weight of a fruit, or the temperature of a room are all examples of continuous data. Therefore, the correct answer is D. References: [Discrete vs Continuous Data: Definition and Examples - Statistics How To], [Discrete Data - Definition and Examples | Math Goodies]

• Question 125:

  A recurring event is being stored in two databases that are housed in different geographical locations. A data analyst notices the event is being logged three hours earlier in one database than in the other database. Which of the following is the MOST likely cause of the issue?

  A. The data analyst is not querying the databases correctly.

  B. The databases are recording different events.

  C. The databases are recording the event in different time zones.

  D. The second database is logging incorrectly.

  Correct Answer: C

  Explanation: The most likely cause of the issue is that the databases are recording the event in different time zones. A time zone is a region that observes a uniform standard time for legal, commercial, and social purposes. Different time zones have different offsets from Coordinated Universal Time (UTC), which is the primary time standard by which the world regulates clocks and time. For example, UTC-5 is five hours behind UTC, while UTC+3 is three hours ahead of UTC. If an event is being stored in two databases that are housed in different geographical locations with different time zones, it may appear that the event is being logged at different times, depending on how the databases handle the time zone conversion. For example, if one database records the event in UTC-5 and another database records the event in UTC+3, then an event that occurs at 12:00 PM in UTC-5 will appear as 9:00 AM in UTC+3. The other options are not likely causes of the issue, as they are either unrelated or implausible. The data analyst is not querying the databases incorrectly, as this would not affect the time stamps of the events. The databases are not recording different events, as they are supposed to record the same recurring event. The second database is not logging incorrectly, as there is no evidence or reason to assume that. Reference: [Time zone - Wikipedia]

• Question 126:

  What role in a data governance is typically responsible for day-to-day oversight of data use?

  A. Data processors.

  B. Data custodians

  C. Data owners.

  D. Data stewards.

  Correct Answer: D

• Question 127:

  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?

  A. A workbook with multiple tabs for each region

  B. A daily email with snapshots of regional summaries

  C. A static report with a different page for every filtered view

  D. A dashboard with filters at the top that the user can toggle

  Correct Answer: D

  Explanation: The best format to deliver this report is D. A dashboard with filters at the top that the user can toggle. A 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 glance1 A dashboard with filters at the top that the user can toggle would allow the user to easily and quickly access the information they need about various regions, products, and time periods, without having to navigate through multiple tabs, pages, or emails. A dashboard with filters would also enable the user to compare and contrast different views of the data and see how they change over time. A dashboard with filters would also be more interactive and engaging than a static or email report2 A workbook with multiple tabs for each region would not be an efficient way to deliver this report, because it would require the user to switch between different tabs to see the information they need. This would make it harder to compare and contrast different regions, products, and time periods, and also increase the risk of errors or confusion. A workbook with multiple tabs would also be less visually appealing and more cluttered than a dashboard3 A daily email with snapshots of regional summaries would not be an efficient way to deliver this report, because it would limit the user's ability to explore the data in depth and customize their view. A daily email would also be dependent on the frequency and timing of the email delivery, which might not match the user's needs or preferences. A daily email would also be more likely to be ignored or deleted than a dashboard that is always accessible. A static report with a different page for every filtered view would not be an efficient way to deliver this report, because it would create a very long and cumbersome report that would be difficult to read and understand. A static report would also not allow the user to change or update the filters as they wish, or see how the data changes over time. A static report would also be less interactive and engaging than a dashboard.

• Question 128:

  A data analyst is designing a dashboard that will provide a story of sales and determine which site is providing the highest sales volume per customer The analyst must choose an appropriate chart to include in the dashboard. The following data is available: Which of the following types of charts should be considered?

  

  A. Include a line chart using the site and average sales per customer.

  B. Include a pie chart using the site and sales to average sales per customer.

  C. Include a scatter chart using sales volume and average sales per customer.

  D. Include a column chart using the site and sales to average sales per customer.

  Correct Answer: D

  The best type of chart to display the data is D. Include a column chart using the site and sales to average sales per customer. A column chart is a good choice for comparing categorical data with numerical data, such as the site and sales to average sales per customer. A column chart can show the relative differences between the sites and highlight the site with the highest sales volume per customer. A column chart can also be easily labeled and formatted to make the data clear and understandable. A line chart is not suitable for this data, because it is used to show trends or changes over time, which is not relevant for the site and sales to average sales per customer data. A line chart would also be confusing and misleading, as it would imply a connection or correlation between the sites that does not exist. A pie chart is also not a good choice for this data, because it is used to show the proportion of a whole, not the comparison of different categories. A pie chart would also be difficult to read and interpret, as it would require labels or legends to identify the sites and their sales to average sales per customer. A pie chart would also not be able to show the exact values of the sales to average sales per customer, only their relative sizes. A scatter chart is another inappropriate option for this data, because it is used to show the relationship or correlation between two numerical variables, not between a categorical and a numerical variable. A scatter chart would also be cluttered and unclear, as it would plot each site as a point on a coordinate plane, without any labels or axes. A scatter chart would also not be able to show the differences or rankings between the sites and their sales to average sales per customer.

• Question 129:

  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: B

  Explanation: The mean height for the five dogs is 405mm. The mean, or average, is a measure of central tendency that represents the sum of all values divided by the number of values. To calculate the mean height for the five dogs, we can

  use the following formula:

  Mean = (300 + 430 + 170 + 470 + 600) / 5 = 2020 / 5 = 404 We can round up the result to the nearest millimeter, which is 405mm. The other options are not correct, as they are either too high or too low than the actual mean. Reference:

  [Mean - Math is Fun]

• Question 130:

  You would like to measure how well an organization is achieving its goals.

  What type of analysis should you perform?

  A. Performance analysis.

  B. Outlier analysis.

  C. Predictive analysis.

  D. Trend analysis.

  Correct Answer: A

  Performance analysis is the technique of studying or comparing the performance of a specific situation in contrast to the aim and yet executed. In Human Resources, performance analysis can help to review an employee's contribution towards a project or assignment, which they allotted him or her.