Finding the Third Proportional to 638,139 and 987,979.50

Step by Step Solution

1. Step 1: Write the proportion equation
   638,139 : 987,979.50 = 987,979.50 : x
2. Step 2: Convert to fraction form
   638,139/987,979.50 = 987,979.50/x
3. Step 3: Cross multiply
   638,139x = 987,979.50 × 987,979.50
4. Step 4: Simplify right side
   638,139x = 976,103,492,420.25
5. Step 5: Solve for x
   x = 976,103,492,420.25/638,139
6. Step 6: Final answer
   x = 1,529,609.52