Finding the Third Proportional to 261,111 and 390,676.50

Step by Step Solution

1. Step 1: Write the proportion equation
   261,111 : 390,676.50 = 390,676.50 : x
2. Step 2: Convert to fraction form
   261,111/390,676.50 = 390,676.50/x
3. Step 3: Cross multiply
   261,111x = 390,676.50 × 390,676.50
4. Step 4: Simplify right side
   261,111x = 152,628,127,652.25
5. Step 5: Solve for x
   x = 152,628,127,652.25/261,111
6. Step 6: Final answer
   x = 584,533.50