Finding the Fourth Proportional to 200,585.58, 276,838.59 and 128,019.78

Step by Step Solution

1. Step 1: Write the proportion equation
   200,585.58 : 276,838.59 = 128,019.78 : x
2. Step 2: Convert to fraction form
   200,585.58/276,838.59 = 128,019.78/x
3. Step 3: Cross multiply
   200,585.58x = 276,838.59 × 128,019.78
4. Step 4: Simplify right side
   200,585.58x = 35,440,815,387.31
5. Step 5: Solve for x
   x = 35,440,815,387.31/200,585.58
6. Step 6: Final answer
   x = 176,686.76