Finding the Fourth Proportional to 1,111.76, 1,667.34 and 381.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.76 : 1,667.34 = 381.50 : x
2. Step 2: Convert to fraction form
   1,111.76/1,667.34 = 381.50/x
3. Step 3: Cross multiply
   1,111.76x = 1,667.34 × 381.50
4. Step 4: Simplify right side
   1,111.76x = 636,090.21
5. Step 5: Solve for x
   x = 636,090.21/1,111.76
6. Step 6: Final answer
   x = 572.15