Finding the Third Proportional to 256,189.50 and 385,109.25

Step by Step Solution

1. Step 1: Write the proportion equation
   256,189.50 : 385,109.25 = 385,109.25 : x
2. Step 2: Convert to fraction form
   256,189.50/385,109.25 = 385,109.25/x
3. Step 3: Cross multiply
   256,189.50x = 385,109.25 × 385,109.25
4. Step 4: Simplify right side
   256,189.50x = 148,309,134,435.56
5. Step 5: Solve for x
   x = 148,309,134,435.56/256,189.50
6. Step 6: Final answer
   x = 578,904.03