Finding the Fourth Proportional to 21,830.62, 30,124.86 and 12,878.50

Step by Step Solution

1. Step 1: Write the proportion equation
   21,830.62 : 30,124.86 = 12,878.50 : x
2. Step 2: Convert to fraction form
   21,830.62/30,124.86 = 12,878.50/x
3. Step 3: Cross multiply
   21,830.62x = 30,124.86 × 12,878.50
4. Step 4: Simplify right side
   21,830.62x = 387,963,009.51
5. Step 5: Solve for x
   x = 387,963,009.51/21,830.62
6. Step 6: Final answer
   x = 17,771.51