Finding the Fourth Proportional to 1,111.10, 1,666.94 and 380.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.10 : 1,666.94 = 380.69 : x
2. Step 2: Convert to fraction form
   1,111.10/1,666.94 = 380.69/x
3. Step 3: Cross multiply
   1,111.10x = 1,666.94 × 380.69
4. Step 4: Simplify right side
   1,111.10x = 634,577.15
5. Step 5: Solve for x
   x = 634,577.15/1,111.10
6. Step 6: Final answer
   x = 571.13