Finding the Third Proportional to 688,429 and 991,531.50

Step by Step Solution

1. Step 1: Write the proportion equation
   688,429 : 991,531.50 = 991,531.50 : x
2. Step 2: Convert to fraction form
   688,429/991,531.50 = 991,531.50/x
3. Step 3: Cross multiply
   688,429x = 991,531.50 × 991,531.50
4. Step 4: Simplify right side
   688,429x = 983,134,715,492.25
5. Step 5: Solve for x
   x = 983,134,715,492.25/688,429
6. Step 6: Final answer
   x = 1,428,084.40