Answer:
Part 1) The ratio is

Part 2) The height is

Explanation:
Part 1)
Let
x ----> the wide of the monitor
y ----> the height of the monitor
z ----> the aspect ratio of a laptop monitor

we have

Multiply both numerator and denominator by 1,000

Simplify
Divide by 125 both numerator and denominator

Part 2) If the Monitor is 15 inches wide, what is the height?
we know that

we have

substitute the given values and solve for y

therefore
The height is 9.23 in