Finding the Fourth Proportional to 389,904.72, 538,069.36 and 211,056.72

Step by Step Solution

1. Step 1: Write the proportion equation
   389,904.72 : 538,069.36 = 211,056.72 : x
2. Step 2: Convert to fraction form
   389,904.72/538,069.36 = 211,056.72/x
3. Step 3: Cross multiply
   389,904.72x = 538,069.36 × 211,056.72
4. Step 4: Simplify right side
   389,904.72x = 113,563,154,254.10
5. Step 5: Solve for x
   x = 113,563,154,254.10/389,904.72
6. Step 6: Final answer
   x = 291,258.73