Finding the Fourth Proportional to 1,105.90, 1,656.15 and 1,057.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,105.90 : 1,656.15 = 1,057.30 : x
2. Step 2: Convert to fraction form
   1,105.90/1,656.15 = 1,057.30/x
3. Step 3: Cross multiply
   1,105.90x = 1,656.15 × 1,057.30
4. Step 4: Simplify right side
   1,105.90x = 1,751,047.40
5. Step 5: Solve for x
   x = 1,751,047.40/1,105.90
6. Step 6: Final answer
   x = 1,583.37