Finding the Fourth Proportional to 257,422.72, 355,242.88 and 156,820.72

Step by Step Solution

1. Step 1: Write the proportion equation
   257,422.72 : 355,242.88 = 156,820.72 : x
2. Step 2: Convert to fraction form
   257,422.72/355,242.88 = 156,820.72/x
3. Step 3: Cross multiply
   257,422.72x = 355,242.88 × 156,820.72
4. Step 4: Simplify right side
   257,422.72x = 55,709,444,216.47
5. Step 5: Solve for x
   x = 55,709,444,216.47/257,422.72
6. Step 6: Final answer
   x = 216,412.31