Finding the Fourth Proportional to 21,012.98, 31,518.62 and 5,218.04

Step by Step Solution

1. Step 1: Write the proportion equation
   21,012.98 : 31,518.62 = 5,218.04 : x
2. Step 2: Convert to fraction form
   21,012.98/31,518.62 = 5,218.04/x
3. Step 3: Cross multiply
   21,012.98x = 31,518.62 × 5,218.04
4. Step 4: Simplify right side
   21,012.98x = 164,465,419.90
5. Step 5: Solve for x
   x = 164,465,419.90/21,012.98
6. Step 6: Final answer
   x = 7,826.85