Finding the Third Proportional to 261,255 and 390,868.50

Step by Step Solution

1. Step 1: Write the proportion equation
   261,255 : 390,868.50 = 390,868.50 : x
2. Step 2: Convert to fraction form
   261,255/390,868.50 = 390,868.50/x
3. Step 3: Cross multiply
   261,255x = 390,868.50 × 390,868.50
4. Step 4: Simplify right side
   261,255x = 152,778,184,292.25
5. Step 5: Solve for x
   x = 152,778,184,292.25/261,255
6. Step 6: Final answer
   x = 584,785.69