Finding the Fourth Proportional to 138,897.05, 191,709.38 and 78,502.72

Step by Step Solution

1. Step 1: Write the proportion equation
   138,897.05 : 191,709.38 = 78,502.72 : x
2. Step 2: Convert to fraction form
   138,897.05/191,709.38 = 78,502.72/x
3. Step 3: Cross multiply
   138,897.05x = 191,709.38 × 78,502.72
4. Step 4: Simplify right side
   138,897.05x = 15,049,707,779.51
5. Step 5: Solve for x
   x = 15,049,707,779.51/138,897.05
6. Step 6: Final answer
   x = 108,351.53