Question

Solve for the variable in the following proportion.

4 is to 5 as 10 is to a

8
12
12.5
20

Answer 1

12.5

Explanation:

4/5=10/x

cross product

5*10=4*x

50=4x

x=50/4

simplify,

x=25/2

x=12.5

Answer 2

(c) The value of variable a is 12.5.

Explanation:

4 is to 5 as 10 is to a.

or, 4 : 5 = 10 : a

By the RATIO OF PROPORTIONALITY:

`(4)/(5)  = (10)/(a)  \\\implies a = (10 * 5)/(4)  = 12. 5`

or, the value of a = 12. 5

⇒ 4 is to 5 as 10 is to 12.5

Hence, the value of variable a is 12.5.