Finding the Fourth Proportional to 139,072.56, 191,894.48 and 81,721.22

Step by Step Solution

1. Step 1: Write the proportion equation
   139,072.56 : 191,894.48 = 81,721.22 : x
2. Step 2: Convert to fraction form
   139,072.56/191,894.48 = 81,721.22/x
3. Step 3: Cross multiply
   139,072.56x = 191,894.48 × 81,721.22
4. Step 4: Simplify right side
   139,072.56x = 15,681,851,494.33
5. Step 5: Solve for x
   x = 15,681,851,494.33/139,072.56
6. Step 6: Final answer
   x = 112,760.21