Finding the Fourth Proportional to 139,061.57, 191,903.80 and 78,644.08

Step by Step Solution

1. Step 1: Write the proportion equation
   139,061.57 : 191,903.80 = 78,644.08 : x
2. Step 2: Convert to fraction form
   139,061.57/191,903.80 = 78,644.08/x
3. Step 3: Cross multiply
   139,061.57x = 191,903.80 × 78,644.08
4. Step 4: Simplify right side
   139,061.57x = 15,092,097,799.50
5. Step 5: Solve for x
   x = 15,092,097,799.50/139,061.57
6. Step 6: Final answer
   x = 108,528.17