Finding the Fourth Proportional to 128,377.89, 177,158.18 and 71,015.72

Step by Step Solution

1. Step 1: Write the proportion equation
   128,377.89 : 177,158.18 = 71,015.72 : x
2. Step 2: Convert to fraction form
   128,377.89/177,158.18 = 71,015.72/x
3. Step 3: Cross multiply
   128,377.89x = 177,158.18 × 71,015.72
4. Step 4: Simplify right side
   128,377.89x = 12,581,014,465.72
5. Step 5: Solve for x
   x = 12,581,014,465.72/128,377.89
6. Step 6: Final answer
   x = 97,999.85