Finding the Fourth Proportional to 139,068.42, 191,918.19 and 78,648.10

Step by Step Solution

1. Step 1: Write the proportion equation
   139,068.42 : 191,918.19 = 78,648.10 : x
2. Step 2: Convert to fraction form
   139,068.42/191,918.19 = 78,648.10/x
3. Step 3: Cross multiply
   139,068.42x = 191,918.19 × 78,648.10
4. Step 4: Simplify right side
   139,068.42x = 15,094,000,666.61
5. Step 5: Solve for x
   x = 15,094,000,666.61/139,068.42
6. Step 6: Final answer
   x = 108,536.51