Finding the Fourth Proportional to 1,111.60, 1,667.49 and 380.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.60 : 1,667.49 = 380.98 : x
2. Step 2: Convert to fraction form
   1,111.60/1,667.49 = 380.98/x
3. Step 3: Cross multiply
   1,111.60x = 1,667.49 × 380.98
4. Step 4: Simplify right side
   1,111.60x = 635,280.34
5. Step 5: Solve for x
   x = 635,280.34/1,111.60
6. Step 6: Final answer
   x = 571.50