Finding the Fourth Proportional to 21,290.61, 31,940.86 and 7,250.76

Step by Step Solution

1. Step 1: Write the proportion equation
   21,290.61 : 31,940.86 = 7,250.76 : x
2. Step 2: Convert to fraction form
   21,290.61/31,940.86 = 7,250.76/x
3. Step 3: Cross multiply
   21,290.61x = 31,940.86 × 7,250.76
4. Step 4: Simplify right side
   21,290.61x = 231,595,347.65
5. Step 5: Solve for x
   x = 231,595,347.65/21,290.61
6. Step 6: Final answer
   x = 10,877.82