To determine the ratio of the number of families that own a dog, simply divide the number of families that own a dog by the total number of families.
[tex]\frac{number\text{ }of\text{ }families\text{ }that\text{ }owns\text{ }a\text{ }dog}{total\text{ }number\text{ }of\text{ }families}[/tex][tex]\frac{8}{24}[/tex]Simplify the fraction by dividing both number and denominator by 8.
[tex]\frac{8\div8}{24\div8}=\frac{1}{3}[/tex]Therefore, the ratio that represents the number of families that own a dog is 1:3. This means that one out of three families owns a dog.