Finding the Fourth Proportional to 138,561.23, 191,198.25 and 78,128.27

Step by Step Solution

1. Step 1: Write the proportion equation
   138,561.23 : 191,198.25 = 78,128.27 : x
2. Step 2: Convert to fraction form
   138,561.23/191,198.25 = 78,128.27/x
3. Step 3: Cross multiply
   138,561.23x = 191,198.25 × 78,128.27
4. Step 4: Simplify right side
   138,561.23x = 14,937,988,499.53
5. Step 5: Solve for x
   x = 14,937,988,499.53/138,561.23
6. Step 6: Final answer
   x = 107,807.85