Finding the Fourth Proportional to 1,365.87, 1,885.05 and 776.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,365.87 : 1,885.05 = 776.55 : x
2. Step 2: Convert to fraction form
   1,365.87/1,885.05 = 776.55/x
3. Step 3: Cross multiply
   1,365.87x = 1,885.05 × 776.55
4. Step 4: Simplify right side
   1,365.87x = 1,463,835.58
5. Step 5: Solve for x
   x = 1,463,835.58/1,365.87
6. Step 6: Final answer
   x = 1,071.72