Finding the Fourth Proportional to 128,900.69, 177,883.59 and 72,312.06

Step by Step Solution

1. Step 1: Write the proportion equation
   128,900.69 : 177,883.59 = 72,312.06 : x
2. Step 2: Convert to fraction form
   128,900.69/177,883.59 = 72,312.06/x
3. Step 3: Cross multiply
   128,900.69x = 177,883.59 × 72,312.06
4. Step 4: Simplify right side
   128,900.69x = 12,863,128,833.10
5. Step 5: Solve for x
   x = 12,863,128,833.10/128,900.69
6. Step 6: Final answer
   x = 99,791.00