Finding the Fourth Proportional to 1,080.78, 1,484.30 and 905.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,080.78 : 1,484.30 = 905.82 : x
2. Step 2: Convert to fraction form
   1,080.78/1,484.30 = 905.82/x
3. Step 3: Cross multiply
   1,080.78x = 1,484.30 × 905.82
4. Step 4: Simplify right side
   1,080.78x = 1,344,504.10
5. Step 5: Solve for x
   x = 1,344,504.10/1,080.78
6. Step 6: Final answer
   x = 1,244.01