Finding the Fourth Proportional to 21,328.39, 31,925.10 and 13,403.48

Step by Step Solution

1. Step 1: Write the proportion equation
   21,328.39 : 31,925.10 = 13,403.48 : x
2. Step 2: Convert to fraction form
   21,328.39/31,925.10 = 13,403.48/x
3. Step 3: Cross multiply
   21,328.39x = 31,925.10 × 13,403.48
4. Step 4: Simplify right side
   21,328.39x = 427,907,279.72
5. Step 5: Solve for x
   x = 427,907,279.72/21,328.39
6. Step 6: Final answer
   x = 20,062.81