Finding the Fourth Proportional to 1,284.78, 1,771.83 and 842.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,284.78 : 1,771.83 = 842.52 : x
2. Step 2: Convert to fraction form
   1,284.78/1,771.83 = 842.52/x
3. Step 3: Cross multiply
   1,284.78x = 1,771.83 × 842.52
4. Step 4: Simplify right side
   1,284.78x = 1,492,802.21
5. Step 5: Solve for x
   x = 1,492,802.21/1,284.78
6. Step 6: Final answer
   x = 1,161.91