Finding the Fourth Proportional to 1,405.89, 1,940.10 and 776.41

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.89 : 1,940.10 = 776.41 : x
2. Step 2: Convert to fraction form
   1,405.89/1,940.10 = 776.41/x
3. Step 3: Cross multiply
   1,405.89x = 1,940.10 × 776.41
4. Step 4: Simplify right side
   1,405.89x = 1,506,299.46
5. Step 5: Solve for x
   x = 1,506,299.46/1,405.89
6. Step 6: Final answer
   x = 1,071.42