Finding the Third Proportional to 386,217 and 577,131.75

Step by Step Solution

1. Step 1: Write the proportion equation
   386,217 : 577,131.75 = 577,131.75 : x
2. Step 2: Convert to fraction form
   386,217/577,131.75 = 577,131.75/x
3. Step 3: Cross multiply
   386,217x = 577,131.75 × 577,131.75
4. Step 4: Simplify right side
   386,217x = 333,081,056,858.06
5. Step 5: Solve for x
   x = 333,081,056,858.06/386,217
6. Step 6: Final answer
   x = 862,419.46