No, \( P \times Q \neq Q \times P \).
The Cartesian product \( P \times Q \) is defined as the set of all ordered pairs \( (p, q) \) where \( p \) is from set \( P \) and \( q \) is from set \( Q \). For \( P = {8, 4} \) and \( Q = {3, 5} \):
\[ P \times Q = {(8, 3), (8, 5), (4, 3), (4, 5)} \]
Similarly, the Cartesian product \( Q \times P \) is:
\[ Q \times P = {(3, 8), (3, 4), (5, 8), (5, 4)} \]
As you can see, the ordered pairs in \( P \times Q \) and \( Q \times P \) are different. Therefore, they are not equal.