Hat sizes are determined by measuring the circumference of the head in either inches or centimeters?

use ratio and proportions to complete the following table

Hat size =7 Head circumference inches = 22 and Centimeters =56

and If hat size was 6 3/4 Head circumference in inches would = ? and in centimeters would = ?

2 answers

6 3/4 : x = 7 : 22

7x = 148.5
x = 21.21 inches

Go ahead and do the same thing for the circumference in centimeters -- remembering that the answer will be a little less than 56.

We'll be glad to check your answer.
C / 6.75 = 22in / 7, C = 6.75*22/7 =21in

C / 6.75 = 56 / 7, C = 6.75*56/7 = 54cm