Finding the Fourth Proportional to 1,111.71, 1,667.72 and 381.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.71 : 1,667.72 = 381.09 : x
2. Step 2: Convert to fraction form
   1,111.71/1,667.72 = 381.09/x
3. Step 3: Cross multiply
   1,111.71x = 1,667.72 × 381.09
4. Step 4: Simplify right side
   1,111.71x = 635,551.41
5. Step 5: Solve for x
   x = 635,551.41/1,111.71
6. Step 6: Final answer
   x = 571.69