Finding the Fourth Proportional to 9,900.81, 13,662.74 and 5,919.55

Step by Step Solution

1. Step 1: Write the proportion equation
   9,900.81 : 13,662.74 = 5,919.55 : x
2. Step 2: Convert to fraction form
   9,900.81/13,662.74 = 5,919.55/x
3. Step 3: Cross multiply
   9,900.81x = 13,662.74 × 5,919.55
4. Step 4: Simplify right side
   9,900.81x = 80,877,253.21
5. Step 5: Solve for x
   x = 80,877,253.21/9,900.81
6. Step 6: Final answer
   x = 8,168.75