Finding the Third Proportional to 128,776.50 and 189,308.25

Step by Step Solution

1. Step 1: Write the proportion equation
   128,776.50 : 189,308.25 = 189,308.25 : x
2. Step 2: Convert to fraction form
   128,776.50/189,308.25 = 189,308.25/x
3. Step 3: Cross multiply
   128,776.50x = 189,308.25 × 189,308.25
4. Step 4: Simplify right side
   128,776.50x = 35,837,613,518.06
5. Step 5: Solve for x
   x = 35,837,613,518.06/128,776.50
6. Step 6: Final answer
   x = 278,293.12