Finding the Fourth Proportional to 12,621.30, 17,415.40 and 7,315.05

Step by Step Solution

1. Step 1: Write the proportion equation
   12,621.30 : 17,415.40 = 7,315.05 : x
2. Step 2: Convert to fraction form
   12,621.30/17,415.40 = 7,315.05/x
3. Step 3: Cross multiply
   12,621.30x = 17,415.40 × 7,315.05
4. Step 4: Simplify right side
   12,621.30x = 127,394,521.77
5. Step 5: Solve for x
   x = 127,394,521.77/12,621.30
6. Step 6: Final answer
   x = 10,093.61