Finding the Fourth Proportional to 8,919.42, 12,308.77 and 5,142.57

Step by Step Solution

1. Step 1: Write the proportion equation
   8,919.42 : 12,308.77 = 5,142.57 : x
2. Step 2: Convert to fraction form
   8,919.42/12,308.77 = 5,142.57/x
3. Step 3: Cross multiply
   8,919.42x = 12,308.77 × 5,142.57
4. Step 4: Simplify right side
   8,919.42x = 63,298,711.34
5. Step 5: Solve for x
   x = 63,298,711.34/8,919.42
6. Step 6: Final answer
   x = 7,096.73