Answer
$\dfrac{4}{5} \text{ or } 80\%$
Work Step by Step
The quarterback made $45$ passes and out of those $45$ passes, only $36$ were complete.
To find the probability, you divide the number of passes that were completed which was $36$ by the total numbers of passes made which was $45$:
Thus, the probability that the next pass will be completed it:
$=\dfrac{36}{45}$
$=\dfrac{4}{5}$
$=80\%$
