Finding the Fourth Proportional to 10,921.40, 16,373.20 and 3,421.10

Step by Step Solution

1. Step 1: Write the proportion equation
   10,921.40 : 16,373.20 = 3,421.10 : x
2. Step 2: Convert to fraction form
   10,921.40/16,373.20 = 3,421.10/x
3. Step 3: Cross multiply
   10,921.40x = 16,373.20 × 3,421.10
4. Step 4: Simplify right side
   10,921.40x = 56,014,279.37
5. Step 5: Solve for x
   x = 56,014,279.37/10,921.40
6. Step 6: Final answer
   x = 5,128.86