Finding the Fourth Proportional to 139,015.84, 208,491.78 and 82,871.80

Step by Step Solution

1. Step 1: Write the proportion equation
   139,015.84 : 208,491.78 = 82,871.80 : x
2. Step 2: Convert to fraction form
   139,015.84/208,491.78 = 82,871.80/x
3. Step 3: Cross multiply
   139,015.84x = 208,491.78 × 82,871.80
4. Step 4: Simplify right side
   139,015.84x = 17,278,089,093.80
5. Step 5: Solve for x
   x = 17,278,089,093.80/139,015.84
6. Step 6: Final answer
   x = 124,288.64