Finding the Fourth Proportional to 21,820.90, 30,112.88 and 12,389.46

Step by Step Solution

1. Step 1: Write the proportion equation
   21,820.90 : 30,112.88 = 12,389.46 : x
2. Step 2: Convert to fraction form
   21,820.90/30,112.88 = 12,389.46/x
3. Step 3: Cross multiply
   21,820.90x = 30,112.88 × 12,389.46
4. Step 4: Simplify right side
   21,820.90x = 373,082,471.14
5. Step 5: Solve for x
   x = 373,082,471.14/21,820.90
6. Step 6: Final answer
   x = 17,097.48