Finding the Fourth Proportional to 9,411.62, 12,987.51 and 5,378.30

Step by Step Solution

1. Step 1: Write the proportion equation
   9,411.62 : 12,987.51 = 5,378.30 : x
2. Step 2: Convert to fraction form
   9,411.62/12,987.51 = 5,378.30/x
3. Step 3: Cross multiply
   9,411.62x = 12,987.51 × 5,378.30
4. Step 4: Simplify right side
   9,411.62x = 69,850,725.03
5. Step 5: Solve for x
   x = 69,850,725.03/9,411.62
6. Step 6: Final answer
   x = 7,421.75