Finding the Fourth Proportional to 389,917.50, 538,087.59 and 211,069.50

Step by Step Solution

1. Step 1: Write the proportion equation
   389,917.50 : 538,087.59 = 211,069.50 : x
2. Step 2: Convert to fraction form
   389,917.50/538,087.59 = 211,069.50/x
3. Step 3: Cross multiply
   389,917.50x = 538,087.59 × 211,069.50
4. Step 4: Simplify right side
   389,917.50x = 113,573,878,577.51
5. Step 5: Solve for x
   x = 113,573,878,577.51/389,917.50
6. Step 6: Final answer
   x = 291,276.69