Finding the Fourth Proportional to 1,111.26, 1,666.58 and 380.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.26 : 1,666.58 = 380.59 : x
2. Step 2: Convert to fraction form
   1,111.26/1,666.58 = 380.59/x
3. Step 3: Cross multiply
   1,111.26x = 1,666.58 × 380.59
4. Step 4: Simplify right side
   1,111.26x = 634,280.47
5. Step 5: Solve for x
   x = 634,280.47/1,111.26
6. Step 6: Final answer
   x = 570.78