This question says Let JK be the median of ABTQ and find JK.
here is the picture to go by attached!!!
AB is the median of trapezoid QRST.
The length of the median of a trapezoid is one-half the sum of the lengths of the two bases.
$\displaystyle AB=\frac{RS+QT}{2}$
Substitute known values for RS and QT and solve for AB.
Since JK is a median of trapezoid ABTQ,
$\displaystyle JK=\frac{AB+QT}{2}$
All variables except JK should be known at this point, so substitute values for AB and QT and find JK.