Finding the Fourth Proportional to 12,620.25, 17,421.42 and 7,907.28

Step by Step Solution

1. Step 1: Write the proportion equation
   12,620.25 : 17,421.42 = 7,907.28 : x
2. Step 2: Convert to fraction form
   12,620.25/17,421.42 = 7,907.28/x
3. Step 3: Cross multiply
   12,620.25x = 17,421.42 × 7,907.28
4. Step 4: Simplify right side
   12,620.25x = 137,756,045.94
5. Step 5: Solve for x
   x = 137,756,045.94/12,620.25
6. Step 6: Final answer
   x = 10,915.48