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Quiz: groupby and merge

5 questionsNo time limitPass: 60%+10 XP on first pass

Answer real questions with pandas: groupby with split-apply-combine, several aggregations at once, joining tables with merge (inner, left, outer), and pivot tables — through a college placement-report case study.

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  1. Question 1

    Students has 8 rows; a left merge with offers gives 9 rows. What is the most likely reason?

  2. Question 2

    Which join keeps only rows whose key exists in BOTH tables?

  3. Question 3

    How do you find students with no offer after a left merge?

  4. Question 4

    What does pivot_table(index="company", columns="branch", aggfunc="count") show?

  5. Question 5

    Why keep each student's best offer before computing placement rates?