Finding the Fourth Proportional to 9,108.90, 12,570.53 and 5,129.78

Step by Step Solution

1. Step 1: Write the proportion equation
   9,108.90 : 12,570.53 = 5,129.78 : x
2. Step 2: Convert to fraction form
   9,108.90/12,570.53 = 5,129.78/x
3. Step 3: Cross multiply
   9,108.90x = 12,570.53 × 5,129.78
4. Step 4: Simplify right side
   9,108.90x = 64,483,964.88
5. Step 5: Solve for x
   x = 64,483,964.88/9,108.90
6. Step 6: Final answer
   x = 7,079.23