Finding the Fourth Proportional to 21,023.10, 31,521.69 and 7,868.70

Step by Step Solution

1. Step 1: Write the proportion equation
   21,023.10 : 31,521.69 = 7,868.70 : x
2. Step 2: Convert to fraction form
   21,023.10/31,521.69 = 7,868.70/x
3. Step 3: Cross multiply
   21,023.10x = 31,521.69 × 7,868.70
4. Step 4: Simplify right side
   21,023.10x = 248,034,722.10
5. Step 5: Solve for x
   x = 248,034,722.10/21,023.10
6. Step 6: Final answer
   x = 11,798.20