Finding the Fourth Proportional to 784.56, 1,085.46 and 770.76

Step by Step Solution

1. Step 1: Write the proportion equation
   784.56 : 1,085.46 = 770.76 : x
2. Step 2: Convert to fraction form
   784.56/1,085.46 = 770.76/x
3. Step 3: Cross multiply
   784.56x = 1,085.46 × 770.76
4. Step 4: Simplify right side
   784.56x = 836,629.15
5. Step 5: Solve for x
   x = 836,629.15/784.56
6. Step 6: Final answer
   x = 1,066.37