Finding the Fourth Proportional to 9,113.40, 12,561.72 and 7,120.48

Step by Step Solution

1. Step 1: Write the proportion equation
   9,113.40 : 12,561.72 = 7,120.48 : x
2. Step 2: Convert to fraction form
   9,113.40/12,561.72 = 7,120.48/x
3. Step 3: Cross multiply
   9,113.40x = 12,561.72 × 7,120.48
4. Step 4: Simplify right side
   9,113.40x = 89,445,476.03
5. Step 5: Solve for x
   x = 89,445,476.03/9,113.40
6. Step 6: Final answer
   x = 9,814.72