Answer:
7.8 pounds
Step-by-step explanation:
The relation between pounds and kilograms is proportional:
[tex]\dfrac{\text{books}}{3.5\text{ kg}}=\dfrac{1\text{ lb}}{0.45\text{ kg}}\qquad\text{pounds to kg proportion}\\\\\text{books}=\dfrac{(3.5\text{ kg})(1\text{ lb})}{0.45\text{ kg}}=\dfrac{3.5}{0.45}\text{ lb}\qquad\text{multiply by 3.5 kg}\\\\\boxed{\text{books}\approx7.8\text{ lb}}[/tex]
The stack of books weighs about 7.8 pounds.
