Finding the Fourth Proportional to 8,123.51, 12,187.39 and 2,858.31

Step by Step Solution

1. Step 1: Write the proportion equation
   8,123.51 : 12,187.39 = 2,858.31 : x
2. Step 2: Convert to fraction form
   8,123.51/12,187.39 = 2,858.31/x
3. Step 3: Cross multiply
   8,123.51x = 12,187.39 × 2,858.31
4. Step 4: Simplify right side
   8,123.51x = 34,835,270.63
5. Step 5: Solve for x
   x = 34,835,270.63/8,123.51
6. Step 6: Final answer
   x = 4,288.21