Finding the Third Proportional to 387,909 and 579,514.50

Step by Step Solution

1. Step 1: Write the proportion equation
   387,909 : 579,514.50 = 579,514.50 : x
2. Step 2: Convert to fraction form
   387,909/579,514.50 = 579,514.50/x
3. Step 3: Cross multiply
   387,909x = 579,514.50 × 579,514.50
4. Step 4: Simplify right side
   387,909x = 335,837,055,710.25
5. Step 5: Solve for x
   x = 335,837,055,710.25/387,909
6. Step 6: Final answer
   x = 865,762.47