Finding the Third Proportional to 319,648.50 and 689,112

Step by Step Solution

1. Step 1: Write the proportion equation
   319,648.50 : 689,112 = 689,112 : x
2. Step 2: Convert to fraction form
   319,648.50/689,112 = 689,112/x
3. Step 3: Cross multiply
   319,648.50x = 689,112 × 689,112
4. Step 4: Simplify right side
   319,648.50x = 474,875,348,544
5. Step 5: Solve for x
   x = 474,875,348,544/319,648.50
6. Step 6: Final answer
   x = 1,485,617.32