Finding the Fourth Proportional to 21,691, 32,514.34 and 12,311.20

Step by Step Solution

1. Step 1: Write the proportion equation
   21,691 : 32,514.34 = 12,311.20 : x
2. Step 2: Convert to fraction form
   21,691/32,514.34 = 12,311.20/x
3. Step 3: Cross multiply
   21,691x = 32,514.34 × 12,311.20
4. Step 4: Simplify right side
   21,691x = 400,290,542.61
5. Step 5: Solve for x
   x = 400,290,542.61/21,691
6. Step 6: Final answer
   x = 18,454.22