Answer
x=818
Work Step by Step
Set the product of the means equal to the product of the extremes and solve for the variable.
$442\times55.7=30.1\times x$
$24619.4=30.1x$
$24619.4\div30.1=30.1x\div30.1$
$x=81\underset\uparrow7.920$
Since the digit to the right of the 3rd significant digit is greater than 5, round up.