Finding the Fourth Proportional to 28,131.90, 42,191.57 and 8,407.89

Step by Step Solution

1. Step 1: Write the proportion equation
   28,131.90 : 42,191.57 = 8,407.89 : x
2. Step 2: Convert to fraction form
   28,131.90/42,191.57 = 8,407.89/x
3. Step 3: Cross multiply
   28,131.90x = 42,191.57 × 8,407.89
4. Step 4: Simplify right side
   28,131.90x = 354,742,053.21
5. Step 5: Solve for x
   x = 354,742,053.21/28,131.90
6. Step 6: Final answer
   x = 12,609.96