Finding the Fourth Proportional to 1,367.09, 1,886.30 and 869.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,367.09 : 1,886.30 = 869.55 : x
2. Step 2: Convert to fraction form
   1,367.09/1,886.30 = 869.55/x
3. Step 3: Cross multiply
   1,367.09x = 1,886.30 × 869.55
4. Step 4: Simplify right side
   1,367.09x = 1,640,227.82
5. Step 5: Solve for x
   x = 1,640,227.82/1,367.09
6. Step 6: Final answer
   x = 1,199.80