Given:
54 gal of hot water tank holds 450 lb of water.
Let's find the amount of water a 69 gal tank will hold.
Here, we have:
54 gal = 450 lb
69 gal = x lb
Now, apply the proportionality equation:

Cross multiply:

Divide both sides by 54:

Therefore, a 69 gal tank will hold 575 lb of water.
ANSWER:
575 lb of water