Finding the Fourth Proportional to 128,667.42, 177,586.29 and 77,688.54

Step by Step Solution

1. Step 1: Write the proportion equation
   128,667.42 : 177,586.29 = 77,688.54 : x
2. Step 2: Convert to fraction form
   128,667.42/177,586.29 = 77,688.54/x
3. Step 3: Cross multiply
   128,667.42x = 177,586.29 × 77,688.54
4. Step 4: Simplify right side
   128,667.42x = 13,796,419,594.12
5. Step 5: Solve for x
   x = 13,796,419,594.12/128,667.42
6. Step 6: Final answer
   x = 107,225.43