Finding the Fourth Proportional to 875.52, 1,313.98 and 820.78

Step by Step Solution

1. Step 1: Write the proportion equation
   875.52 : 1,313.98 = 820.78 : x
2. Step 2: Convert to fraction form
   875.52/1,313.98 = 820.78/x
3. Step 3: Cross multiply
   875.52x = 1,313.98 × 820.78
4. Step 4: Simplify right side
   875.52x = 1,078,488.50
5. Step 5: Solve for x
   x = 1,078,488.50/875.52
6. Step 6: Final answer
   x = 1,231.83