Finding the Third Proportional to 256,716 and 385,870.50

Step by Step Solution

1. Step 1: Write the proportion equation
   256,716 : 385,870.50 = 385,870.50 : x
2. Step 2: Convert to fraction form
   256,716/385,870.50 = 385,870.50/x
3. Step 3: Cross multiply
   256,716x = 385,870.50 × 385,870.50
4. Step 4: Simplify right side
   256,716x = 148,896,042,770.25
5. Step 5: Solve for x
   x = 148,896,042,770.25/256,716
6. Step 6: Final answer
   x = 580,002.97