Finding the Fourth Proportional to 1,343.55, 1,857.18 and 1,121.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,343.55 : 1,857.18 = 1,121.20 : x
2. Step 2: Convert to fraction form
   1,343.55/1,857.18 = 1,121.20/x
3. Step 3: Cross multiply
   1,343.55x = 1,857.18 × 1,121.20
4. Step 4: Simplify right side
   1,343.55x = 2,082,270.22
5. Step 5: Solve for x
   x = 2,082,270.22/1,343.55
6. Step 6: Final answer
   x = 1,549.83