Finding the Fourth Proportional to 128,623, 177,499.78 and 72,034.38

Step by Step Solution

1. Step 1: Write the proportion equation
   128,623 : 177,499.78 = 72,034.38 : x
2. Step 2: Convert to fraction form
   128,623/177,499.78 = 72,034.38/x
3. Step 3: Cross multiply
   128,623x = 177,499.78 × 72,034.38
4. Step 4: Simplify right side
   128,623x = 12,786,086,602.44
5. Step 5: Solve for x
   x = 12,786,086,602.44/128,623
6. Step 6: Final answer
   x = 99,407.47