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## Statistics and probability

### Course: Statistics and probability>Unit 6

Lesson 4: Types of studies (experimental vs. observational)

# Types of statistical studies

## Problem

The mayor of Statville had to decide how to allocate her education budget between the two high schools in town, “Stat Sticks” and “Datum High.” To decide which school deserves a bigger portion of the budget, she wanted to assess which school is more helpful to its students.
She went over the grade sheets of the students from both schools in the past $5$ years. For each student, she calculated the difference between scores on their high school entrance and exit exams. Then, she compared the average difference for the students from each school.
What type of statistical study did the mayor use?