Finding the Fourth Proportional to 2,131.40, 2,940.81 and 1,199.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,131.40 : 2,940.81 = 1,199.90 : x
2. Step 2: Convert to fraction form
   2,131.40/2,940.81 = 1,199.90/x
3. Step 3: Cross multiply
   2,131.40x = 2,940.81 × 1,199.90
4. Step 4: Simplify right side
   2,131.40x = 3,528,663.21
5. Step 5: Solve for x
   x = 3,528,663.21/2,131.40
6. Step 6: Final answer
   x = 1,655.57