Finding the Fourth Proportional to 1,648.10, 2,470.04 and 780.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,648.10 : 2,470.04 = 780.50 : x
2. Step 2: Convert to fraction form
   1,648.10/2,470.04 = 780.50/x
3. Step 3: Cross multiply
   1,648.10x = 2,470.04 × 780.50
4. Step 4: Simplify right side
   1,648.10x = 1,927,862.32
5. Step 5: Solve for x
   x = 1,927,862.32/1,648.10
6. Step 6: Final answer
   x = 1,169.75