Finding the Third Proportional to 261,276 and 390,898.50

Step by Step Solution

1. Step 1: Write the proportion equation
   261,276 : 390,898.50 = 390,898.50 : x
2. Step 2: Convert to fraction form
   261,276/390,898.50 = 390,898.50/x
3. Step 3: Cross multiply
   261,276x = 390,898.50 × 390,898.50
4. Step 4: Simplify right side
   261,276x = 152,801,637,302.25
5. Step 5: Solve for x
   x = 152,801,637,302.25/261,276
6. Step 6: Final answer
   x = 584,828.45