Finding the Fourth Proportional to 139,857.99, 193,017.96 and 85,407.15

Step by Step Solution

1. Step 1: Write the proportion equation
   139,857.99 : 193,017.96 = 85,407.15 : x
2. Step 2: Convert to fraction form
   139,857.99/193,017.96 = 85,407.15/x
3. Step 3: Cross multiply
   139,857.99x = 193,017.96 × 85,407.15
4. Step 4: Simplify right side
   139,857.99x = 16,485,113,435.38
5. Step 5: Solve for x
   x = 16,485,113,435.38/139,857.99
6. Step 6: Final answer
   x = 117,870.38