Answer:
16.35
Explanation:
Using an inverse normal distribution, we can calculate the z score given the percentile, which can then be used to find our value.
First, we can use an inverse normal distribution calculator to figure out that the z score given the 75th percentile is 0.674.
Next, we know that the z score is (observed value - mean) / standard deviation. We can plug our values in to get

Rounding, we get x = 16.35 as our answer