In order to find the cost of the piece of chocolate, we can use a rule of three.
The cost of one pound of chocolate is $7.70, so the cost of 0.11 pound of chocolate would be x:
[tex]\begin{gathered} 1\text{ pound}\to7.7 \\ 0.11\text{ pound}\to x \\ \\ \frac{1}{0.11}=\frac{7.7}{x} \\ x=7.7\cdot0.11 \\ x=0.847 \end{gathered}[/tex]Rounding to the nearest hundredth, the cost will be $0.85.
So the student solution is not correct. The student should multiply 0.11 by 7.70, and not divide them.
