Finding the Fourth Proportional to 1,434.78, 1,980.16 and 805.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,434.78 : 1,980.16 = 805.48 : x
2. Step 2: Convert to fraction form
   1,434.78/1,980.16 = 805.48/x
3. Step 3: Cross multiply
   1,434.78x = 1,980.16 × 805.48
4. Step 4: Simplify right side
   1,434.78x = 1,594,972.31
5. Step 5: Solve for x
   x = 1,594,972.31/1,434.78
6. Step 6: Final answer
   x = 1,111.65