Finding the Fourth Proportional to 1,111.69, 1,668.39 and 1,054.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.69 : 1,668.39 = 1,054.59 : x
2. Step 2: Convert to fraction form
   1,111.69/1,668.39 = 1,054.59/x
3. Step 3: Cross multiply
   1,111.69x = 1,668.39 × 1,054.59
4. Step 4: Simplify right side
   1,111.69x = 1,759,467.41
5. Step 5: Solve for x
   x = 1,759,467.41/1,111.69
6. Step 6: Final answer
   x = 1,582.70