a test for memory is done on students, but the researcher forgot to first determine their level of english proficiency

If this is a question that need a answer of how they could fix it, they could get some/a students that spoke that language or hire a translator. (Sorry if this is so off track and not what you needed--)  Grades could help if they did not know how well they spoke English. (8th, 6th, etc.) Speaking to their teacher or parents could also help them know.

Explanation:

we can solve this via the kinematic equation:

where the vertical velocity is zero and so:

since the height of the building is 29.3 meters then:

the ball was in motion for approximately 2.45 seconds