Finding the Fourth Proportional to 1,648.86, 2,474.54 and 783.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,648.86 : 2,474.54 = 783.78 : x
2. Step 2: Convert to fraction form
   1,648.86/2,474.54 = 783.78/x
3. Step 3: Cross multiply
   1,648.86x = 2,474.54 × 783.78
4. Step 4: Simplify right side
   1,648.86x = 1,939,494.96
5. Step 5: Solve for x
   x = 1,939,494.96/1,648.86
6. Step 6: Final answer
   x = 1,176.26