Across product is an equation which states that two ratios are equal. true or false

it's equivalent, so we can say that its equal.

let's call the denominator x and the numerador is 18 less then denominator, x - 18.

multiply

2.x = 5.(x - 18)

2x = 5x - 90

90 = 5x - 2x

90 = 3x

x = 90/3

x = 30

so:

one fourth of 9% = 2.25%

gavin is correct in saying : the equivalent quarterly interest rate would be

2.25%.