Answer
108 lb
Work Step by Step
Create a proportion using ratios of bu : lb.
$\frac{100\ bu}{90\ lb}=\frac{120\ bu}{x\ lb}$
Set the product of the means equal to the product of the extremes and solve for the variable.
$90\times 120 = 100\times x$
$10800=100x$
$10800\div100=100x\div100$
$108=x$
