Finding the Fourth Proportional to 20,585.61, 28,397.69 and 13,019.19

Step by Step Solution

1. Step 1: Write the proportion equation
   20,585.61 : 28,397.69 = 13,019.19 : x
2. Step 2: Convert to fraction form
   20,585.61/28,397.69 = 13,019.19/x
3. Step 3: Cross multiply
   20,585.61x = 28,397.69 × 13,019.19
4. Step 4: Simplify right side
   20,585.61x = 369,714,856.58
5. Step 5: Solve for x
   x = 369,714,856.58/20,585.61
6. Step 6: Final answer
   x = 17,959.87