Finding the Fourth Proportional to 1,111.42, 1,666.78 and 380.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.42 : 1,666.78 = 380.82 : x
2. Step 2: Convert to fraction form
   1,111.42/1,666.78 = 380.82/x
3. Step 3: Cross multiply
   1,111.42x = 1,666.78 × 380.82
4. Step 4: Simplify right side
   1,111.42x = 634,743.16
5. Step 5: Solve for x
   x = 634,743.16/1,111.42
6. Step 6: Final answer
   x = 571.11