Finding the Fourth Proportional to 139,315.88, 209,009.18 and 64,490

Step by Step Solution

1. Step 1: Write the proportion equation
   139,315.88 : 209,009.18 = 64,490 : x
2. Step 2: Convert to fraction form
   139,315.88/209,009.18 = 64,490/x
3. Step 3: Cross multiply
   139,315.88x = 209,009.18 × 64,490
4. Step 4: Simplify right side
   139,315.88x = 13,479,002,018.20
5. Step 5: Solve for x
   x = 13,479,002,018.20/139,315.88
6. Step 6: Final answer
   x = 96,751.37