Finding the Third Proportional to 128,236.50 and 280,074

Step by Step Solution

1. Step 1: Write the proportion equation
   128,236.50 : 280,074 = 280,074 : x
2. Step 2: Convert to fraction form
   128,236.50/280,074 = 280,074/x
3. Step 3: Cross multiply
   128,236.50x = 280,074 × 280,074
4. Step 4: Simplify right side
   128,236.50x = 78,441,445,476
5. Step 5: Solve for x
   x = 78,441,445,476/128,236.50
6. Step 6: Final answer
   x = 611,693.59