Finding the Fourth Proportional to 1,111.46, 1,667.76 and 853.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.46 : 1,667.76 = 853.12 : x
2. Step 2: Convert to fraction form
   1,111.46/1,667.76 = 853.12/x
3. Step 3: Cross multiply
   1,111.46x = 1,667.76 × 853.12
4. Step 4: Simplify right side
   1,111.46x = 1,422,799.41
5. Step 5: Solve for x
   x = 1,422,799.41/1,111.46
6. Step 6: Final answer
   x = 1,280.12