Finding the Fourth Proportional to 9,414.51, 12,990.60 and 5,380.65

Step by Step Solution

1. Step 1: Write the proportion equation
   9,414.51 : 12,990.60 = 5,380.65 : x
2. Step 2: Convert to fraction form
   9,414.51/12,990.60 = 5,380.65/x
3. Step 3: Cross multiply
   9,414.51x = 12,990.60 × 5,380.65
4. Step 4: Simplify right side
   9,414.51x = 69,897,871.89
5. Step 5: Solve for x
   x = 69,897,871.89/9,414.51
6. Step 6: Final answer
   x = 7,424.48