Module 3: Database Essentials Answers (Part 3: Q31–41)
This is Part 3 of the Module 3 quiz answers for “Database Essentials” from the Google Data Analytics Professional Certificate on Coursera.
Here, we’ll walk through questions 31 to 41 with detailed explanations to support your learning.
To find answers to the remaining questions, check out the full module breakdown below:
31. What are some key benefits of using external data? Select all that apply.
- External data is always reliable.
- External data is free to use.
- External data has broad reach. ✅
- External data can provide industry-level perspectives. ✅
Explanation:
External data gives insights that are outside the scope of internal business operations. It helps understand market trends, customer preferences, competitor behavior, and industry-wide benchmarks.
- Broad reach refers to the wide variety of data sources and scope it covers.
- Industry-level perspectives help compare performance or spot opportunities in the market.
32. A data analyst reviews a national database of movie theater showings. They want to find the first movies shown in San Francisco in 2001. How can they organize the data to return the first 10 movies shown at the top of their list? Select all that apply.
- Filter out showings not in 2001 ✅
- Sort by date in descending order
- Sort by date in ascending order ✅
- Filter out showings outside of San Francisco ✅
Explanation:
To find the first 10 movies shown, you need:
- Data from 2001 only
- Showings in San Francisco only
- Then sort by date in ascending order (oldest to newest) to get the earliest ones at the top
33. You are working with a database table that contains customer data. The state column lists the state where each customer is located. The state names are abbreviated. You want to find out which customers are located in the state of Florida (FL).
You write the SQL query below. Add a WHERE clause that will return only customers located in FL.
How many customers are located in FL?
- 6
- 4
- 1 ✅
- 3
Explanation:
The SQL query SELECT * FROM customer WHERE state = 'FL' will return only the customers located in Florida. The output will show that there is 1 customer in FL.
34. Structural metadata indicates how a piece of data is organized and whether it’s part of one or more than one data collection.
- True ✅
- False
Explanation:
Structural metadata describes the organization of data, such as its format, relationships, and whether it belongs to one or multiple collections.
35. Relational databases illustrate relationships between tables. Which fields represent the connection between these tables? Select all that apply.
- Foreign keys ✅
- External keys
- Primary keys ✅
- Secondary keys
Explanation:
In relational databases, primary keys uniquely identify each record in a table, and foreign keys establish a link between two tables by referencing the primary key of another table.
36. When writing a query, you must remove the two backticks around the name of the dataset in order for the query to run properly.
- True
- False ✅
Explanation:
In SQL, backticks are used to enclose dataset or column names, especially when they are reserved keywords or contain spaces. They are necessary in some cases, so removing them would cause an error.
37. You are working with a database table that contains customer data. The first_name column lists the first name of each customer. You are only interested in customers with the first name Mark.
You write the SQL query below. Add a WHERE clause that will return only customers named Mark.
How many customers are named Mark?
- 1
- 5
- 3
- 2 ✅
Explanation:
Using the query:SELECT * FROM customer WHERE first_name = ‘Mark’;
This returns all customers with the first name Mark. In the given dataset, there are 2 such customers.
38. Metadata is data about data. What kinds of information can metadata offer about a particular dataset? Select all that apply.
- How to combine the data with another dataset ✅
- Which analyses to perform on the data
- If the data is clean and reliable ✅
- What kinds of data it contains ✅
Explanation:
Metadata can describe:
- Data types
- Source and reliability
- Cleaning status
- Relationships to other datasets
It doesn’t tell you directly what analysis to perform—that’s up to the analyst based on goals.
39. A data analyst reviews a database of Wisconsin car sales to find the last car models sold in Milwaukee in 2019. How can they sort and filter the data to return the last five cars sold at the top of their list? Select all that apply.
- Filter out sales outside of Milwaukee ✅
- Filter out sales not in 2019 ✅
- Sort by sale date in descending order ✅
- Sort by sale date in ascending order
Explanation:
The analyst can filter by location (Milwaukee) and time (2019), and sort by the sale date in descending order to return the most recent sales.
40. When writing a query, the name of the dataset can either be inside two backticks, or not, and the query will still run properly.
- True ✅
- False
Explanation:
In many SQL environments (like BigQuery or MySQL), you can omit backticks if the name doesn’t contain special characters or keywords. But it’s best practice to use them when necessary.
41. A data analyst chooses not to use external data because it represents diverse perspectives. This is an appropriate decision when working with external data.
- True
- False ✅
Explanation:
Diverse perspectives are a strength of external data. They help reduce bias and provide a more well-rounded understanding of a situation. Rejecting data just because it’s diverse is not appropriate.
Congratulations! You’ve completed all questions. Share this post if it helped you, and check out other Coursera quiz answers below.
Related contents:
Module 1: Data types and structures
Module 2: Data responsibility
Module 4: Organize and protect data
Module 6: *Course challenge*
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