Finding the Fourth Proportional to 22,479.42, 31,020.93 and 12,920.88

Step by Step Solution

1. Step 1: Write the proportion equation
   22,479.42 : 31,020.93 = 12,920.88 : x
2. Step 2: Convert to fraction form
   22,479.42/31,020.93 = 12,920.88/x
3. Step 3: Cross multiply
   22,479.42x = 31,020.93 × 12,920.88
4. Step 4: Simplify right side
   22,479.42x = 400,817,714.02
5. Step 5: Solve for x
   x = 400,817,714.02/22,479.42
6. Step 6: Final answer
   x = 17,830.43