Finding the Fourth Proportional to 1,209.82, 1,667.78 and 854.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,209.82 : 1,667.78 = 854.64 : x
2. Step 2: Convert to fraction form
   1,209.82/1,667.78 = 854.64/x
3. Step 3: Cross multiply
   1,209.82x = 1,667.78 × 854.64
4. Step 4: Simplify right side
   1,209.82x = 1,425,351.50
5. Step 5: Solve for x
   x = 1,425,351.50/1,209.82
6. Step 6: Final answer
   x = 1,178.15