Finding the Fourth Proportional to 1,054.85, 1,455.71 and 612.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,054.85 : 1,455.71 = 612.78 : x
2. Step 2: Convert to fraction form
   1,054.85/1,455.71 = 612.78/x
3. Step 3: Cross multiply
   1,054.85x = 1,455.71 × 612.78
4. Step 4: Simplify right side
   1,054.85x = 892,019.63
5. Step 5: Solve for x
   x = 892,019.63/1,054.85
6. Step 6: Final answer
   x = 845.64