Finding the Third Proportional to 686,666 and 1,061,139

Step by Step Solution

1. Step 1: Write the proportion equation
   686,666 : 1,061,139 = 1,061,139 : x
2. Step 2: Convert to fraction form
   686,666/1,061,139 = 1,061,139/x
3. Step 3: Cross multiply
   686,666x = 1,061,139 × 1,061,139
4. Step 4: Simplify right side
   686,666x = 1,126,015,977,321
5. Step 5: Solve for x
   x = 1,126,015,977,321/686,666
6. Step 6: Final answer
   x = 1,639,830.69