Answer:
10.92 inches
Explanation:
Use a proportion. Set up two ratios equal to each other.
Given ratio:
The ratio of months to inches of growth is
1 month : 1.68 inches or 1/1.68
Now set up a ratio involving the unknown amount.
6 1/2 is the same as 6.5
In 6.5 months, he grows x inches.
6.5 months : x inches, or 6.5/x
Set the ratios equal creating a proportion.
Cross multiply.
1 * x = 1.68 * 6.5
x = 10.92
Answer: 10.92 inches