Finding the Fourth Proportional to 35,878.80, 53,810.72 and 13,687.20

Step by Step Solution

1. Step 1: Write the proportion equation
   35,878.80 : 53,810.72 = 13,687.20 : x
2. Step 2: Convert to fraction form
   35,878.80/53,810.72 = 13,687.20/x
3. Step 3: Cross multiply
   35,878.80x = 53,810.72 × 13,687.20
4. Step 4: Simplify right side
   35,878.80x = 736,518,086.78
5. Step 5: Solve for x
   x = 736,518,086.78/35,878.80
6. Step 6: Final answer
   x = 20,527.95