Google Data Analytics Certificate Readiness Quiz: SQL, Spreadsheets, and Visualization

Updated on May 23, 2026. Google Data Analytics Certificate curriculum details verified against Google Career Certificates on Coursera.

Google Data Analytics Certificate Readiness Quiz: SQL, Spreadsheets, and Visualization

The Google Data Analytics Certificate on Coursera covers spreadsheets (Google Sheets), SQL, R programming, Tableau, data cleaning, and exploratory data analysis across 8 courses. It typically takes 6 months at ~10 hours per week and costs approximately $49/month (~$294 total). This quiz tests whether you already have the foundational knowledge the certificate builds — or whether you are walking in cold and should plan for the full 6-month timeline.

For a detailed breakdown of whether the certificate is worth pursuing for your specific career stage, see tips for completing the Google DA certificate faster. Try the SimpuTech Google Data Analytics AI tutor for adaptive practice on the tools and concepts the certificate covers.

Work through all 15 questions, then check your score against the bands below for personalized next-step recommendations.

SQL Questions

Question 1

What does the following SQL query return?
SELECT employee_name, salary FROM employees WHERE salary > 50000 ORDER BY salary DESC;

1. A) All columns from the employees table, sorted alphabetically
2. B) The names and salaries of employees earning more than $50,000, sorted from highest to lowest salary
3. C) The count of employees earning more than $50,000
4. D) All employees, with those earning more than $50,000 highlighted

Answer: B. SELECT specifies which columns to return (employee_name and salary). WHERE filters rows to those with salary greater than 50,000. ORDER BY salary DESC sorts results from highest to lowest. The query returns only the filtered subset, not all rows.

Question 2

What is the difference between an INNER JOIN and a LEFT JOIN?

1. A) INNER JOIN returns all rows from both tables; LEFT JOIN returns only matching rows
2. B) INNER JOIN returns only rows where both tables have matching values; LEFT JOIN returns all rows from the left table plus matching rows from the right table
3. C) They produce identical results when both tables have no NULL values
4. D) LEFT JOIN is faster than INNER JOIN on large tables

Answer: B. INNER JOIN returns the intersection — rows that have matching keys in both tables. LEFT JOIN returns all rows from the left table, filling right-table columns with NULL when there is no match. This distinction matters when analyzing incomplete data: a LEFT JOIN preserves all customers even if they have no orders; an INNER JOIN silently drops customers with no orders.

Question 3

What does GROUP BY do in a SQL query?

1. A) Sorts rows alphabetically by the specified column
2. B) Removes duplicate rows from results
3. C) Groups rows with the same values in the specified column together, enabling aggregate functions like COUNT, SUM, or AVG to be applied per group
4. D) Filters rows based on aggregate conditions

Answer: C. GROUP BY collapses multiple rows with the same value into a single row, allowing you to calculate aggregates per group. For example: SELECT department, COUNT(*) FROM employees GROUP BY department counts employees in each department. Option D describes HAVING, not GROUP BY.

Spreadsheet Questions

Question 4

In Google Sheets, the formula =VLOOKUP(A2, D:F, 2, FALSE) does which of the following?

1. A) Looks up the value in cell A2 in column D, and returns the value from column E (2nd column of D:F range), requiring an exact match
2. B) Looks up the value in cell A2 in all three columns D, E, and F
3. C) Returns the second row of the range D:F
4. D) Calculates the average of the first two columns in D:F

Answer: A. VLOOKUP syntax: =VLOOKUP(lookup_value, table_array, col_index_num, [range_lookup]). The lookup_value (A2) is searched in the first column of the range (D). The col_index_num (2) returns the value from the 2nd column of the range (E). FALSE requires an exact match. Common error: candidates confuse col_index_num with column letter — it is a number relative to the range, not the spreadsheet column.

Question 5

What does a pivot table do?

1. A) Rearranges rows and columns to display data in a different visual order
2. B) Summarizes data by grouping values and calculating aggregates (sum, count, average) across categories, making large datasets explorable
3. C) Converts raw data into a line chart
4. D) Filters rows based on criteria and hides unmatched rows

Answer: B. Pivot tables transform row-level data into aggregated summaries by category. A dataset with 10,000 rows of sales transactions can be pivoted to show total revenue by region, by month, and by product category simultaneously — without writing any formulas. They are one of the most important tools in the Google DA certificate curriculum.

Data Visualization Questions

Question 6

You want to show how total sales have changed month over month for the past year. Which chart type is most appropriate?

1. A) Bar chart
2. B) Pie chart
3. C) Line chart
4. D) Scatter plot

Answer: C. Line charts show change over time — they are ideal for continuous data across time periods. Bar charts compare discrete categories (month-by-month totals are fine as bars, but line charts better communicate trend direction). Pie charts show part-to-whole proportions. Scatter plots show correlation between two continuous variables.

Question 7

In Tableau, what is the difference between a dimension and a measure?

1. A) Dimensions are numerical; measures are categorical
2. B) Dimensions are categorical fields used to slice and group data; measures are numerical fields that can be aggregated
3. C) Dimensions appear on the y-axis; measures appear on the x-axis
4. D) Dimensions require a formula; measures are raw data values

Answer: B. In Tableau, dimensions are qualitative fields (Region, Product Category, Customer Name) used to structure your view. Measures are quantitative fields (Sales, Quantity, Profit) that can be summed, averaged, or otherwise aggregated. Understanding this distinction is foundational to building any Tableau visualization.

Data Cleaning Questions

Question 8

You are analyzing a customer dataset and discover that 8% of rows have NULL values in the "age" column. What is the most appropriate first step?

1. A) Delete all rows with NULL age values
2. B) Replace all NULL values with the mean age from the dataset
3. C) Investigate why the NULLs exist — are they random missing data, or a pattern (e.g., all from the same data source)?
4. D) Leave the NULLs as-is and exclude the age column from analysis

Answer: C. Before handling NULLs, understand them. NULLs from a specific data source may indicate a collection error. NULLs concentrated in a certain age group may indicate response bias. The handling method (deletion, imputation, exclusion) should be determined by the root cause. Blindly deleting or replacing NULLs without understanding them can introduce bias into your analysis.

Question 9

What is a primary key in a database table?

1. A) The first column in the table
2. B) The column with the highest number of unique values
3. C) A column or combination of columns that uniquely identifies each row in the table, with no NULL or duplicate values allowed
4. D) A column used to join two tables together

Answer: C. A primary key enforces uniqueness — each value must be unique and non-NULL. It is the definitive identifier for each record. A foreign key (option D describes its use case) references a primary key in another table to create a join relationship. A primary key can be used as a join key, but its defining characteristic is uniqueness within its own table.

Data Analysis and Statistics Questions

Question 10

A dataset of household incomes is strongly right-skewed because a few households earn very high incomes. Which measure of central tendency is more representative of a typical household income?

1. A) Mean
2. B) Median
3. C) Mode
4. D) Range

Answer: B. The median is the middle value when data is sorted and is not affected by extreme outliers. In a right-skewed distribution, the mean is pulled upward by the high-income outliers, making it larger than what most households actually earn. The median better represents the "typical" value. This is why median household income is reported rather than mean household income in economic statistics.

Question 11

In R, what does the filter() function from the tidyverse package do?

1. A) Selects specific columns from a data frame
2. B) Removes rows with missing values
3. C) Returns a subset of rows from a data frame that meet specified conditions
4. D) Sorts rows in ascending or descending order

Answer: C. filter() keeps only rows that satisfy the condition(s) you specify. For example: filter(df, age > 25) returns rows where the age column is greater than 25. This is the R equivalent of SQL's WHERE clause. Option A describes select(). Option D describes arrange().

Question 12

What is the difference between a sample and a population in data analysis?

1. A) A sample is always smaller than a population
2. B) A population includes every member of the group being studied; a sample is a subset drawn from that population to represent it
3. C) Samples are used for historical analysis; populations for predictions
4. D) A population requires more computation than a sample

Answer: B. A population is the complete group of interest (all customers, all products, all transactions). A sample is a representative subset drawn to make inferences about the population. When a full population is unavailable or analyzing it is impractical, sample statistics (mean, proportion) are used to estimate population parameters. Option A is generally true but not the defining characteristic — the defining difference is completeness vs. subset.

Data Ethics Question

Question 13

Which of the following is an example of Personally Identifiable Information (PII)?

1. A) Average order value by region
2. B) A customer's email address and purchase history linked to their name
3. C) Number of active users by day of week
4. D) Aggregated quarterly revenue figures

Answer: B. PII is any information that can be used to identify a specific individual. An email address alone may qualify; combined with a name and purchase history, it is definitively PII. The other options are aggregated or anonymized data that do not identify individuals. Handling PII requires compliance with privacy regulations (GDPR, CCPA) and is a core topic in the Google DA certificate curriculum.

Score bands

• 0–7 correct (start from foundations): Begin with Google DA courses 1–2 (Foundations of Data: Data Everywhere and Ask Questions to Make Data-Driven Decisions). These cover spreadsheet basics, data types, and analytical thinking before introducing SQL and R.
• 8–14 correct (targeted review needed): You have foundational knowledge but gaps in specific tools. Focus on the SQL modules in courses 4–5 and the data visualization section in course 6. Complete all hands-on activities, not just the video lectures.
• 15–20 correct (ready for certificate): Your knowledge base is solid. Move directly to Course 7 (R programming) and Course 8 (Capstone). Completing the capstone case study is the most important differentiator for job applications.