Walk me through one analysis you did from start to finish.
What the interviewer wants to hear
- States the business question and who asked it
- Describes the data sources and how they were cleaned and checked
- Explains the method used and why it fit the question
- Shares the result with a concrete number
- Ends with the recommendation and what happened next
Model answer
At my last internship the marketing lead asked why online orders fell 8% in March. I first agreed on the metric: completed orders, excluding test accounts. I pulled orders, sessions and campaign data with SQL and checked row counts against the order system so I knew the data was complete. Then I broke the drop down by channel, device and region. Almost all of the fall came from mobile users in one city, starting the day a new app version was released. Checkout conversion on that version was half the normal rate. I shared a one-page summary with a chart and the size of the loss, about 1,200 orders a week. The app team found a payment bug, fixed it within days, and orders returned to normal. The key lesson for me was to segment early instead of looking only at the total.
Can you answer it under time pressure?
Take a timed easy round and get scored on every answer.
More easy Data Analyst questions
- Explain the difference between INNER JOIN, LEFT JOIN and FULL OUTER JOIN with a simple example.
- You receive a new dataset from a client. What steps do you take to clean it before analysis?
- When would you use the median instead of the mean? Give a business example.
- How do you decide which chart to use for a piece of data?
- How would you explain a data finding to a manager who is not technical?
- How do you check that the numbers from your SQL query are correct before you share them?
- What is the difference between VLOOKUP and XLOOKUP, and which do you prefer?
- What is the difference between a metric and a KPI? Give an example.
- You find duplicate customer records in a dataset. How do you handle them?