Finding the Fourth Proportional to 91,128.56, 136,671.24 and 28,799.60

Step by Step Solution

1. Step 1: Write the proportion equation
   91,128.56 : 136,671.24 = 28,799.60 : x
2. Step 2: Convert to fraction form
   91,128.56/136,671.24 = 28,799.60/x
3. Step 3: Cross multiply
   91,128.56x = 136,671.24 × 28,799.60
4. Step 4: Simplify right side
   91,128.56x = 3,936,077,043.50
5. Step 5: Solve for x
   x = 3,936,077,043.50/91,128.56
6. Step 6: Final answer
   x = 43,192.57