Finding the Third Proportional to 128,813 and 189,487.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,813 : 189,487.50 = 189,487.50 : x
2. Step 2: Convert to fraction form
   128,813/189,487.50 = 189,487.50/x
3. Step 3: Cross multiply
   128,813x = 189,487.50 × 189,487.50
4. Step 4: Simplify right side
   128,813x = 35,905,512,656.25
5. Step 5: Solve for x
   x = 35,905,512,656.25/128,813
6. Step 6: Final answer
   x = 278,741.37