Are the following ratios in proportion? (Show working)
i. 7: 9 and 10: 14
ii. 6:14 and 9: 21
2007-08-29 13:05:55 · 3 answers · asked by sarah_miss92 1 in Science & Mathematics ➔ Mathematics
If the ratios are in proportion then you should be able to set them equal as fractions.
i. 7:9 and 10:14
7/9 ≠ 10/14
Not in proportion.
ii. 6:14 and 9:21
6/14 = 3/7 = 9/21
In proportion.
2007-08-29 13:22:17 · answer #1 · answered by Northstar 7 · 0⤊ 0⤋
i. 7/9 = X * 10 /14
X = (7 * 14) / ( 9 * 10 ) = 98/90 = 1.089
ratios not in proportion
ii. X = ( 6 * 21 ) / ( 9 * 14 ) = 126 / 126 = 1
yes. ratios in proportion
2007-08-29 13:28:13 · answer #2 · answered by nosf37 4 · 0⤊ 0⤋
I was always taught to cross-multiply problems like these.
so,
7*14=98
9*10=90
the products are not equal thus this set of ratios is not proprtional.
6*21=126
14*9=126
the products are equal, and thus this set of ratios is proportional.
2007-08-29 13:23:52 · answer #3 · answered by BooBoo16 1 · 0⤊ 0⤋