Finding the Fourth Proportional to 128,667.55, 192,787.91 and 91,041.11

Step by Step Solution

1. Step 1: Write the proportion equation
   128,667.55 : 192,787.91 = 91,041.11 : x
2. Step 2: Convert to fraction form
   128,667.55/192,787.91 = 91,041.11/x
3. Step 3: Cross multiply
   128,667.55x = 192,787.91 × 91,041.11
4. Step 4: Simplify right side
   128,667.55x = 17,551,624,865.77
5. Step 5: Solve for x
   x = 17,551,624,865.77/128,667.55
6. Step 6: Final answer
   x = 136,410.66