Mariah has a spinner that has 10 equal sections, each containing a different number from 1 to 10. Mariah determines about how many times the spinner will land on a number that is greater than 7 in 250 spins, and her work is shown below.

P (number greater than 7) = StartFraction Number greater than 7 over Total number of sections EndFraction times number of spins = StartFraction 4 over 10 EndFraction (250) = 100.

What mistake did Mariah make, if any?