Finding the Fourth Proportional to 1,372.48, 1,893.98 and 783.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,372.48 : 1,893.98 = 783.20 : x
2. Step 2: Convert to fraction form
   1,372.48/1,893.98 = 783.20/x
3. Step 3: Cross multiply
   1,372.48x = 1,893.98 × 783.20
4. Step 4: Simplify right side
   1,372.48x = 1,483,371.83
5. Step 5: Solve for x
   x = 1,483,371.83/1,372.48
6. Step 6: Final answer
   x = 1,080.80