Which pair of ratios can form a true proportion?
A: 7/4,21/12 (I CHOOSE THIS)
B: 6/3,5/6
C: 7/10,6/7
D: 3/5,7/12
Pls help
My answer hasn't changed since I posted it for you last night.
http://www.jiskha.com/display.cgi?id=1449973386
To determine if a pair of ratios can form a true proportion, we need to check if the cross products of the ratios are equal. The cross product of a proportion is found by multiplying the numerator of one ratio with the denominator of the other ratio.
Let's calculate the cross products for the given options:
A: 7/4, 21/12
Cross product: (7 * 12) / (4 * 21) = 84 / 84 = 1
B: 6/3, 5/6
Cross product: (6 * 6) / (3 * 5) = 36 / 15 ≠ 1
C: 7/10, 6/7
Cross product: (7 * 7) / (10 * 6) = 49 / 60 ≠ 1
D: 3/5, 7/12
Cross product: (3 * 12) / (5 * 7) = 36 / 35 ≠ 1
From the calculations, only option A: 7/4, 21/12 has cross products that are equal to 1. Therefore, A is the pair of ratios that can form a true proportion.