Finding the Third Proportional to 261,145 and 390,727.50

Step by Step Solution

1. Step 1: Write the proportion equation
   261,145 : 390,727.50 = 390,727.50 : x
2. Step 2: Convert to fraction form
   261,145/390,727.50 = 390,727.50/x
3. Step 3: Cross multiply
   261,145x = 390,727.50 × 390,727.50
4. Step 4: Simplify right side
   261,145x = 152,667,979,256.25
5. Step 5: Solve for x
   x = 152,667,979,256.25/261,145
6. Step 6: Final answer
   x = 584,610.00