Finding the Fourth Proportional to 9,109.61, 12,571.31 and 5,130.80

Step by Step Solution

1. Step 1: Write the proportion equation
   9,109.61 : 12,571.31 = 5,130.80 : x
2. Step 2: Convert to fraction form
   9,109.61/12,571.31 = 5,130.80/x
3. Step 3: Cross multiply
   9,109.61x = 12,571.31 × 5,130.80
4. Step 4: Simplify right side
   9,109.61x = 64,500,788.84
5. Step 5: Solve for x
   x = 64,500,788.84/9,109.61
6. Step 6: Final answer
   x = 7,080.52