Finding the Fourth Proportional to 1,185.76, 1,771.84 and 855.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,185.76 : 1,771.84 = 855.10 : x
2. Step 2: Convert to fraction form
   1,185.76/1,771.84 = 855.10/x
3. Step 3: Cross multiply
   1,185.76x = 1,771.84 × 855.10
4. Step 4: Simplify right side
   1,185.76x = 1,515,100.38
5. Step 5: Solve for x
   x = 1,515,100.38/1,185.76
6. Step 6: Final answer
   x = 1,277.75