The question is an illustrates the use of unit rates
One foot of the board would weigh [tex]1\frac{3}5 lb[/tex]
The parameter is given as:
[tex]4\frac 12 ft = 7\frac 15 lb[/tex] ---- the weight of the board
To calculate the weight of one foot of the board, we simply divide both sides of the equation by [tex]4\frac 12[/tex]
[tex]1 ft = 7\frac 15 lb \div 4\frac 12[/tex]
Express the fraction as an improper fraction
[tex]1 ft = \frac{36}5 lb \div \frac 92[/tex]
Express the division as multiplication
[tex]1 ft = \frac{36}5 lb \times \frac 29[/tex]
Multiply the fractions
[tex]1 ft = \frac{8}5 lb[/tex]
Express the fraction as a mixed number
[tex]1 ft = 1\frac{3}5 lb[/tex]
Hence, the weight of one foot of the board is [tex]1\frac{3}5 lb[/tex]
Read more about unit rates at:
https://brainly.com/question/18065083
