Course 4: Process Data from Dirty to Clean, all weekly challenge quiz answers of this course are provided in this article from week 1 to week 5 to help students solving this exam. Also Check: How to Apply for Coursera Financial Aid
Process Data from Dirty to Clean Weekly Challenge 1 Answers Q1. Which of the following conditions are necessary to ensure data integrity? Select all that apply.
Q2. What is one potential problem associated with data manipulation that analysts must be aware of?
Q3. A data analyst is given a dataset for analysis. It includes data about the total population of every country in the previous 20 years. Based on the available data, an analyst will be able to determine which country was the most populous from 2016 to 2017. Q4. A data analyst is given a dataset for analysis. June 2014 Invoices – Sheet1.csv Which of the following has duplicate data?
Q5. A data analyst is working on a project about the global supply chain. They have a dataset with lots of relevant data from Europe and Asia. However, they decide to generate new data that represents all continents. What type of insufficient data does this scenario describe?
Q6. A car manufacturer wants to learn more about the brand preferences of electric car owners. There are millions of electric car owners in the world. Who should the company survey?
Q7. Fill in the blank: Sampling bias in data collection happens when a sample isn’t representative of _____.
Q8. Which of the following processes helps ensure a close alignment of data and business objectives?
Process Data from Dirty to Clean Weekly Challenge 2 Answers Q1. Which of the following terms describe dirty data? Select all that apply.
Q2. Field length is a spreadsheet tool for determining if a field has been duplicated. Q3. A data analyst notices that the customer in row 2 shares the same Customer ID as the customer in row 6. What does this scenario describe?
Q4. Fill in the blank: Conditional formatting is a spreadsheet tool that changes how _____ appear when values meet a specific condition.
Q5. A data analyst uses the SPLIT function to divide a text string around a specified character and put each fragment into a new, separate cell. What is the specified character separating each item called?
Q6. For a function to work properly, data analysts must follow each function’s predetermined structure. What is this structure called?
Q7. You are working with the following selection of a spreadsheet:
In order to extract the five-digit postal code from Burlington, MA, what is the correct function?
Q8. A data analyst in a human resources department is working with the following selection of a spreadsheet:
They want to create employee identification numbers (IDs) in column D. The IDs should include the year hired plus the last four digits of the employee’s Social Security Number (SS#). What function will create the ID 20093208 for the employee in row 5?
Q9. An analyst is cleaning a new dataset containing 500 rows. They want to make sure the data contained from cell B2 through cell B300 does not contain a number greater than 50. Which of the following COUNTIF function syntaxes could be used to answer this question? Select all that apply.
Q10. The V in VLOOKUP stands for what?
Q11. Fill in the blank: Data mapping is the process of _____ fields from one data source to another.
Q12. Describe the relationship between a primary key and a foreign key.
Process Data from Dirty to Clean Weekly Challenge 3 Answers Q1. Data analysts choose SQL for which of the following reasons? Select all that apply.
Q2. In which of the following situations would a data analyst use spreadsheets instead of SQL? Select all that apply.
Q3. A data analyst creates many new tables in their company’s database. When the project is complete, the analyst wants to remove the tables so they don’t clutter the database. What SQL commands can they use to delete the tables?
Q4. A data analyst is cleaning customer data for an online retail company. They are working with the following section of a database:
The analyst wants to find out if the state data is consistent and if any text strings contain more than two characters. What is the correct SQL clause to use to find any text strings containing more than two characters?
Q5. Fill in the blank: The _____ function counts the number of characters a string contains. Q6. In SQL databases, what data type refers to a number that contains a decimal?
Q7. Fill in the blank: In SQL databases, the _____ function can be used to convert data from one datatype to another. Q8. Fill in the blank: The _____ function can be used to return non-null values in a list.
Process Data from Dirty to Clean Weekly Challenge 4 Answers Q1. The data collected for an analysis project has just been cleaned. What are the next steps for a data analyst? Select all that apply.
Q2. A data analyst is in the verification step. They consider the business problem, the goal, and the data involved in their analytics project. What scenario does this describe?
Q3. Which function removes leading, trailing, and repeated spaces in data? Q4. A data analyst uses the COUNTA function to count which of the following?
Q5. A WHEN statement considers one or more conditions and returns a value as soon as that condition is met. Q6. What is the process of tracking changes, additions, deletions, and errors during data cleaning?
Q7. Fill in the blank: A changelog contains a _____ list of modifications made to a project.
Q8. Reviewing version history is an effective way to view a changelog in SQL. Process Data from Dirty to Clean Course Week 05 Challenge Answers Scenario 1, questions 1-5 Q1. You are a data analyst at a small analytics company. Your company is hosting a project kick-off meeting with a new client, Meer-Kitty Interior Design. The agenda includes reviewing their goals for the year, answering any questions, and discussing their available data. Meer-Kitty Interior Design About Us Page.pdf Meer-Kitty Interior Design Business Plan.pdf Meer-Kitty Interior Design has two goals. They want to expand their online audience, which means getting their company and brand known by as many people as possible. They also want to launch a line of high-quality indoor paint to be sold in-store and online. You decide to consider the data about indoor paint first. Kitty Survey Feedback – Meer-Kitty survey feedback.csv You are pleased to find that the available data is aligned to the business objective. However, you do some research about confidence level for this type of survey and learn that you need at least 120 unique responses for the survey results to be useful. Therefore, the dataset has two limitations: First, there are only 40 responses; second, a Meer-Kitty superfan, User 588, completed the survey 11 times. As the survey has too few responses and numerous duplicates that are skewing results, what are your options? Select all that apply.
Q2. During the meeting, you also learn that Meer-Kitty videos are hosted on their website. For each product offered, there is an accompanying video for customers to learn more. So, more views for a video suggests greater consumer interest. Your goal is to identify which videos are most popular, so Meer-Kitty knows what topics to explore in the future. Unfortunately, Meer-Kitty has just three months of data available because they only recently launched the videos on their site. Without enough data to identify long-term trends about the video subjects that people prefer, what should you do?
Q3. Now that you’ve identified some limitations with Meer-Kitty’s data, you want to communicate your concerns to stakeholders. In addition to insufficient video trend data, your main concern with the indoor paint survey is that the data isn’t representative of the population as a whole. Clearly, one particular respondent, the superfan, is overrepresented. This means the data doesn’t represent the population as a whole. When surveying people for Meer-Kitty in the future, what are some best practices you can use to address some of the issues associated with sampling bias? Select all that apply.
Q4. The stakeholders understand your concerns and agree to repeat the indoor paint survey. In a few weeks, you have a much better dataset with more than 150 responses and no duplicates. Kitty Survey Feedback – New Meer-Kitty survey feedback.csv You notice that questions 4 and 5 are dependent on the respondent’s answer to question 3. So, you need to determine how many people answered Yes to question 3, then compare that to responses to questions 4 and 5. That way, you will know if questions 4 and 5 have any nulls. You decide to use a spreadsheet tool that changes how cells appear when they contain the word Yes. Which tool do you use?
Q5. You continue cleaning the data. You use tools such as remove duplicates and COUNTIF to ensure the dataset is complete, correct, and relevant to the problem you’re trying to solve. Then, you complete the verification and reporting processes to share the details of your data-cleaning effort with your team. While reviewing, your team notes one aspect of data cleaning that would improve the dataset even more. They point out that the new survey also has a new question in Column G: “What are your favorite indoor paint colors?” This was a free-response question, so respondents typed in their answers. Some people included multiple different colors of paint. In order to determine which colors are most popular, it will be necessary to put each color in its own cell. What spreadsheet function enables you to put each of the colors in Column G into a new, separate cell? Scenario 2, questions 6-10 Q6. You’ve completed this program and are interviewing for a junior data scientist position. The job is at B.Spoke Market Research, a company that analyzes market conditions using customer surveys and other research methods. The detailed job description can be found below: C4 B.Spoke Market Research Job Description.pdf So far, you’ve had a phone interview with a recruiter and you’ve secured a second interview with the B.Spoke team. The recruiter’s email can be found below: C4 S2 Email from Recruiter.pdf You arrive 15 minutes early for your interview. Soon, you are escorted into a conference room, where you meet Jodie Choi, the data science lead. After welcoming you, the behavioral interview begins. For your first question, your interviewer wants to learn about your experience with spreadsheets. She says: Sometimes the team needs data that is stored in different spreadsheets. So, we use a spreadsheet function to find the information we need. There is a spreadsheet function that searches for a value in the first column of a given range and returns the value of a specified cell in the row in which it is found. It is called SEARCH. Q7. Next, your interviewer wants to know more about your understanding of tools that work in both spreadsheets and SQL. She explains that the data her team receives from customer surveys sometimes has many duplicate entries. She says: Spreadsheets have a great tool for that called remove duplicates. In SQL, you can include DISTINCT to do the same thing. In which part of the SQL statement do you include DISTINCT?
Q8. Now, your interviewer explains that the data team usually works with very large amounts of customer survey data. After receiving the data, they import it into a SQL table. But sometimes, the new dataset imports incorrectly and they need to change the format. She asks: What function would you use to convert data in a SQL table from one datatype to another?
Q9. Next, your interviewer explains that one of their clients is an online retailer that needs to create product numbers for a vast inventory. Her team does this by combining the text strings for product number, manufacturing date, and color. She asks: Which SQL function would you use to add strings together to create new text strings?
Q10. For your final question, your interviewer explains that her team often comes across data with extra spaces. She asks: Which function would enable you to eliminate those extra spaces? You respond: To eliminate extra spaces for consistency, use the TRIM function. |
What is one potential problem with data manipulation?
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