Finding the Fourth Proportional to 1,139.10, 1,570.88 and 1,054.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.10 : 1,570.88 = 1,054.24 : x
2. Step 2: Convert to fraction form
   1,139.10/1,570.88 = 1,054.24/x
3. Step 3: Cross multiply
   1,139.10x = 1,570.88 × 1,054.24
4. Step 4: Simplify right side
   1,139.10x = 1,656,084.53
5. Step 5: Solve for x
   x = 1,656,084.53/1,139.10
6. Step 6: Final answer
   x = 1,453.85