Finding the Fourth Proportional to 9,155.21, 12,632.67 and 5,378.09

Step by Step Solution

1. Step 1: Write the proportion equation
   9,155.21 : 12,632.67 = 5,378.09 : x
2. Step 2: Convert to fraction form
   9,155.21/12,632.67 = 5,378.09/x
3. Step 3: Cross multiply
   9,155.21x = 12,632.67 × 5,378.09
4. Step 4: Simplify right side
   9,155.21x = 67,939,573.04
5. Step 5: Solve for x
   x = 67,939,573.04/9,155.21
6. Step 6: Final answer
   x = 7,420.87