Solve for the variable in the following proportion.

4 is to 5 as 10 is to a

8
12
12.5
20

(c) The value of variable a  is 12.5.

Step-by-step explanation:

4 is to 5 as 10 is to a.

or, 4 : 5 = 10 : a

By the RATIO OF PROPORTIONALITY:

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.

12.5

Step-by-step explanation:

4/5=10/x

cross product

5*10=4*x

50=4x

x=50/4

simplify,

x=25/2

x=12.5

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