Finding the Fourth Proportional to 3,521.43, 5,280.59 and 1,055.78

Step by Step Solution

1. Step 1: Write the proportion equation
   3,521.43 : 5,280.59 = 1,055.78 : x
2. Step 2: Convert to fraction form
   3,521.43/5,280.59 = 1,055.78/x
3. Step 3: Cross multiply
   3,521.43x = 5,280.59 × 1,055.78
4. Step 4: Simplify right side
   3,521.43x = 5,575,109.63
5. Step 5: Solve for x
   x = 5,575,109.63/3,521.43
6. Step 6: Final answer
   x = 1,583.19