23. Scenario 2, continued
Next, your interviewer explains that one of their clients is an online retailer that has a vast inventory. She has a list of items by name, color, and size. Then, she has another list of the price of each item by size, as a larger item sometimes costs more. The client needs one list of all items by name, color, size, and price.
She then asks: If you were to use the CONCAT function to complete this task, what would it enable you to do?
- Search for and return missing products in inventory
- Create a unique key to tell products apart
- Clean the product identifier text strings
- Create a new product database table
24. Scenario 2, continued
For your final question, your interviewer explains that her team often uses the TRIM function when writing SQL queries.
She asks: What is the TRIM function used for in SQL?
- To eliminate extra leading or trailing spaces
- To return the smallest numeric value from a list
- To shorten the list of results
- To eliminate null values
25. Scenario 1, questions 1-5
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.
Before the meeting you review the About Us tab on their website and their business plan, linked below:
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.
To use the template for the survey feedback, click the link below and select “Use Template.”
Link to template: Kitty Survey Feedback
OR
If you don’t have a Google account, download the file directly from the attachment below.
When you refer to the Meer-Kitty survey feedback tab, 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, you decide to repeat the survey in order to create a new, improved dataset. What is your first step?
- Delete all of the data from the current, skewed survey.
- Write new, improved survey questions.
- Find a survey tool that only allows someone to complete the survey once.
- Talk with stakeholders, explain the new timeline, and ask for approval.
26. Scenario 1 continued
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. What does this situation describe?
- Sampling bias
- Statistical significance
- Margin of error
- Confidence level
27. Scenario 1 continued
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.
To use the template for the survey feedback, click the link below and select “Use Template.”
Link to template: Kitty Survey Feedback
OR
If you don’t have a Google account, download the file directly from the attachment below.
If you are using the template, please refer to the New Meer-Kitty survey feedback tab. 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 meet a certain value — in this case, the word Yes. You are using VLOOKUP.
- True
- False
28. Scenario 2, questions 6-10
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:
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:
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 allows a data analyst to search for a value in the first column of a given range and return the value of a specified cell in the row in which it is found. What function allows you to complete these tasks?
- VLOOKUP
- SEARCH
- COUNTIF
- RETURN
29. Scenario 1, continued
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?
- Divide
- Delimit
- SPLIT
- MID
