Which is the unknown quantity?
8 2/3 yards/ $148.50 = 2 1/3 yards/ ?

Answer: C. $39.98
Step-by-step explanation:
We have the following equation with mixed fractions:
[tex]\frac{8\frac{2}{3}yards}{\$148.50}=\frac{2\frac{1}{3}yards}{?}[/tex] (1)
A mixed fraction is the combination of an integer and a fraction, and to convert it into an improper fraction and be able to solve the equation more easily, we must do the following:
Mixed fraction: [tex]a\frac{b}{c}[/tex]
Converting Mixed fraction to improper fraction: [tex]\frac{(a)(c)+b}{c}[/tex]
So, for both mixed fractions we have:
[tex]8\frac{2}{3}=\frac{26}{3}[/tex]
[tex]2\frac{1}{3}=\frac{7}{3}[/tex]
Having this clear, let's solve the equation:
[tex]\frac{26/3 yards}{\$148.50}=\frac{7/3 yards}{?}[/tex] (2)
[tex]?=\frac{7/3 yards}{26/3 yards}(\$148.50)[/tex] (3)
Finally:
[tex]?=\$39.98[/tex]