Finding the Fourth Proportional to 100,830.42, 139,205.88 and 89,620.38

Step by Step Solution

1. Step 1: Write the proportion equation
   100,830.42 : 139,205.88 = 89,620.38 : x
2. Step 2: Convert to fraction form
   100,830.42/139,205.88 = 89,620.38/x
3. Step 3: Cross multiply
   100,830.42x = 139,205.88 × 89,620.38
4. Step 4: Simplify right side
   100,830.42x = 12,475,683,863.83
5. Step 5: Solve for x
   x = 12,475,683,863.83/100,830.42
6. Step 6: Final answer
   x = 123,729.37