Finding the Fourth Proportional to 128,785.38, 177,723.72 and 72,196.76

Step by Step Solution

1. Step 1: Write the proportion equation
   128,785.38 : 177,723.72 = 72,196.76 : x
2. Step 2: Convert to fraction form
   128,785.38/177,723.72 = 72,196.76/x
3. Step 3: Cross multiply
   128,785.38x = 177,723.72 × 72,196.76
4. Step 4: Simplify right side
   128,785.38x = 12,831,075,870.53
5. Step 5: Solve for x
   x = 12,831,075,870.53/128,785.38
6. Step 6: Final answer
   x = 99,631.46