Finding the Fourth Proportional to 1,106.78, 1,659.45 and 620.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,106.78 : 1,659.45 = 620.15 : x
2. Step 2: Convert to fraction form
   1,106.78/1,659.45 = 620.15/x
3. Step 3: Cross multiply
   1,106.78x = 1,659.45 × 620.15
4. Step 4: Simplify right side
   1,106.78x = 1,029,107.92
5. Step 5: Solve for x
   x = 1,029,107.92/1,106.78
6. Step 6: Final answer
   x = 929.82