Finding the Fourth Proportional to 1,940.78, 2,910.88 and 707.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,940.78 : 2,910.88 = 707.90 : x
2. Step 2: Convert to fraction form
   1,940.78/2,910.88 = 707.90/x
3. Step 3: Cross multiply
   1,940.78x = 2,910.88 × 707.90
4. Step 4: Simplify right side
   1,940.78x = 2,060,593.86
5. Step 5: Solve for x
   x = 2,060,593.86/1,940.78
6. Step 6: Final answer
   x = 1,061.74