Finding the Fourth Proportional to 139,271.83, 209,055.35 and 86,718.31

Step by Step Solution

1. Step 1: Write the proportion equation
   139,271.83 : 209,055.35 = 86,718.31 : x
2. Step 2: Convert to fraction form
   139,271.83/209,055.35 = 86,718.31/x
3. Step 3: Cross multiply
   139,271.83x = 209,055.35 × 86,718.31
4. Step 4: Simplify right side
   139,271.83x = 18,128,926,648.46
5. Step 5: Solve for x
   x = 18,128,926,648.46/139,271.83
6. Step 6: Final answer
   x = 130,169.37