Answer:
17.5 projects in seven hours at a rate of 2.5 projects per hour.
Explanation:
First, find the unit rate of projects per hour.
Next, find the number of projects Ms. Keller would grade in seven hours by multiplying the unit rate by seven hours.
Therefore, at this rate, Ms. Keller will grade 17.5 projects in seven hours at a rate of 2.5 projects per hour.