Finding the Fourth Proportional to 1,411.78, 1,948.26 and 790.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,411.78 : 1,948.26 = 790.78 : x
2. Step 2: Convert to fraction form
   1,411.78/1,948.26 = 790.78/x
3. Step 3: Cross multiply
   1,411.78x = 1,948.26 × 790.78
4. Step 4: Simplify right side
   1,411.78x = 1,540,649.91
5. Step 5: Solve for x
   x = 1,540,649.91/1,411.78
6. Step 6: Final answer
   x = 1,091.28