Finding the Fourth Proportional to 389,917, 538,086.90 and 211,069

Step by Step Solution

1. Step 1: Write the proportion equation
   389,917 : 538,086.90 = 211,069 : x
2. Step 2: Convert to fraction form
   389,917/538,086.90 = 211,069/x
3. Step 3: Cross multiply
   389,917x = 538,086.90 × 211,069
4. Step 4: Simplify right side
   389,917x = 113,573,463,896.10
5. Step 5: Solve for x
   x = 113,573,463,896.10/389,917
6. Step 6: Final answer
   x = 291,276.00