Finding the Fourth Proportional to 389,910.72, 538,077.60 and 211,062.72

Step by Step Solution

1. Step 1: Write the proportion equation
   389,910.72 : 538,077.60 = 211,062.72 : x
2. Step 2: Convert to fraction form
   389,910.72/538,077.60 = 211,062.72/x
3. Step 3: Cross multiply
   389,910.72x = 538,077.60 × 211,062.72
4. Step 4: Simplify right side
   389,910.72x = 113,568,121,827.07
5. Step 5: Solve for x
   x = 113,568,121,827.07/389,910.72
6. Step 6: Final answer
   x = 291,266.99