Finding the Fourth Proportional to 2,131.45, 2,941.20 and 1,187.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,131.45 : 2,941.20 = 1,187.15 : x
2. Step 2: Convert to fraction form
   2,131.45/2,941.20 = 1,187.15/x
3. Step 3: Cross multiply
   2,131.45x = 2,941.20 × 1,187.15
4. Step 4: Simplify right side
   2,131.45x = 3,491,630.87
5. Step 5: Solve for x
   x = 3,491,630.87/2,131.45
6. Step 6: Final answer
   x = 1,638.15