Finding the Fourth Proportional to 1,004.96, 1,386.78 and 612.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,004.96 : 1,386.78 = 612.20 : x
2. Step 2: Convert to fraction form
   1,004.96/1,386.78 = 612.20/x
3. Step 3: Cross multiply
   1,004.96x = 1,386.78 × 612.20
4. Step 4: Simplify right side
   1,004.96x = 848,986.72
5. Step 5: Solve for x
   x = 848,986.72/1,004.96
6. Step 6: Final answer
   x = 844.80