Finding the Fourth Proportional to 1,436.13, 1,980.45 and 1,200.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,436.13 : 1,980.45 = 1,200.42 : x
2. Step 2: Convert to fraction form
   1,436.13/1,980.45 = 1,200.42/x
3. Step 3: Cross multiply
   1,436.13x = 1,980.45 × 1,200.42
4. Step 4: Simplify right side
   1,436.13x = 2,377,371.79
5. Step 5: Solve for x
   x = 2,377,371.79/1,436.13
6. Step 6: Final answer
   x = 1,655.40