Finding the Third Proportional to 320,074.50 and 689,772

Step by Step Solution

1. Step 1: Write the proportion equation
   320,074.50 : 689,772 = 689,772 : x
2. Step 2: Convert to fraction form
   320,074.50/689,772 = 689,772/x
3. Step 3: Cross multiply
   320,074.50x = 689,772 × 689,772
4. Step 4: Simplify right side
   320,074.50x = 475,785,411,984
5. Step 5: Solve for x
   x = 475,785,411,984/320,074.50
6. Step 6: Final answer
   x = 1,486,483.34