Finding the Fourth Proportional to 105,488.72, 145,573.88 and 57,090.64

Step by Step Solution

1. Step 1: Write the proportion equation
   105,488.72 : 145,573.88 = 57,090.64 : x
2. Step 2: Convert to fraction form
   105,488.72/145,573.88 = 57,090.64/x
3. Step 3: Cross multiply
   105,488.72x = 145,573.88 × 57,090.64
4. Step 4: Simplify right side
   105,488.72x = 8,310,905,976.48
5. Step 5: Solve for x
   x = 8,310,905,976.48/105,488.72
6. Step 6: Final answer
   x = 78,784.78