Week 3 Graded Quiz :Managing Big Data with MySQL (Excel to MySQL: Analytic Techniques for Business Specialization) Answers 2025
Answer Key
-
Type of join (Table A & B)
✔ Inner Join
❌ Left Join, Right Join, Full Outer Join -
Type of join (Table A & B)
✔ Right Join
❌ Inner Join, Left Join, Full Outer Join -
Average rating for “yawn warm-up” and “yawn game”
✔ 0.96 and 2.94
❌ Other options -
Activity types with different number of unique user ids and dog ids
✔ 2
❌ 167, 18, 0, 2044 -
Subcategories in exam_answers with total loop numbers >100,000
✔ 12
❌ 30, 1, 3, 2 -
Sorting in retail sales query
✔ By style in descending alphabetical order
❌ Total sum of sales, brand, department, etc. -
COUNT vs COUNT(*) results
✔ Query A: 450,251; Query B: 450,551
❌ Other options -
Complete_tests but NOT in reviews, completed 40 tests
✔ 87
❌ 52, 222, 199, 34 -
Unique mixed breed dogs that completed “Emotions” test
✔ 4,125
❌ 832, 7,299, 36,221, 2,022 -
Top 5 states for unique human users completing “Puzzles” in 2015
✔ CA, TX, FL, IL
❌ N/A -
Unique dogs in site_activities vs reviews
✔ site_activities but not reviews: 24,839; reviews but not site_activities: 5,596
❌ Other options -
Changes to SELECT clause for query to execute
✔ servings → AVG(servings) or MAX(servings)
✔ course → COUNT(course) or COUNT(DISTINCT course)
✔ author → COUNT(author) or COUNT(DISTINCT author)
❌ AVG(calories → calories, add cuisine) -
Shih Tzu dogs weighing 190 lbs
✔ # distinct dogs: 182; average tests: 10.2; min: 0; max: 20
❌ Other options -
Breed completing most tests (only breeds ≥10 dogs)
✔ Breed: Shih Tzu; maximum tests completed: 45
❌ Other options
Summary Table: SQL Joins & Advanced Queries Quiz
| Q# | Topic | Answer / Key Insight |
|---|---|---|
| 1 | Join type | Inner Join |
| 2 | Join type | Right Join |
| 3 | Average game ratings | 0.96 (warm-up), 2.94 (yawn) |
| 4 | Unique user vs dog ids | 2 activity types differ |
| 5 | Subcategories with >100k loops | 12 subcategories |
| 6 | Sorting query | By style descending |
| 7 | COUNT vs COUNT(*) | 450,251 vs 450,551 |
| 8 | Completed 40 tests but not in reviews | 87 dogs |
| 9 | Mixed breed “Emotions” test | 4,125 dogs |
| 10 | Top 5 states, Puzzles test 2015 | CA, TX, FL, IL |
| 11 | Unique dogs site_activities vs reviews | 24,839 vs 5,596 |
| 12 | Fix SELECT for GROUP BY | AVG/ MAX/ COUNT alternatives |
| 13 | Shih Tzu 190 lbs tests | 182 dogs; avg 10.2; min 0; max 20 |
| 14 | Breed with most tests | Shih Tzu; max 45 |