Finding the Fourth Proportional to 1,367.15, 1,886.49 and 777.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,367.15 : 1,886.49 = 777.60 : x
2. Step 2: Convert to fraction form
   1,367.15/1,886.49 = 777.60/x
3. Step 3: Cross multiply
   1,367.15x = 1,886.49 × 777.60
4. Step 4: Simplify right side
   1,367.15x = 1,466,934.62
5. Step 5: Solve for x
   x = 1,466,934.62/1,367.15
6. Step 6: Final answer
   x = 1,072.99