Finding the Fourth Proportional to 2,800.76, 4,201.86 and 853.16

Step by Step Solution

1. Step 1: Write the proportion equation
   2,800.76 : 4,201.86 = 853.16 : x
2. Step 2: Convert to fraction form
   2,800.76/4,201.86 = 853.16/x
3. Step 3: Cross multiply
   2,800.76x = 4,201.86 × 853.16
4. Step 4: Simplify right side
   2,800.76x = 3,584,858.88
5. Step 5: Solve for x
   x = 3,584,858.88/2,800.76
6. Step 6: Final answer
   x = 1,279.96