Finding the Third Proportional to 123,264 and 290,880

Step by Step Solution

1. Step 1: Write the proportion equation
   123,264 : 290,880 = 290,880 : x
2. Step 2: Convert to fraction form
   123,264/290,880 = 290,880/x
3. Step 3: Cross multiply
   123,264x = 290,880 × 290,880
4. Step 4: Simplify right side
   123,264x = 84,611,174,400
5. Step 5: Solve for x
   x = 84,611,174,400/123,264
6. Step 6: Final answer
   x = 686,422.43