Finding the Fourth Proportional to 1,405.38, 1,938.74 and 845.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.38 : 1,938.74 = 845.78 : x
2. Step 2: Convert to fraction form
   1,405.38/1,938.74 = 845.78/x
3. Step 3: Cross multiply
   1,405.38x = 1,938.74 × 845.78
4. Step 4: Simplify right side
   1,405.38x = 1,639,733.59
5. Step 5: Solve for x
   x = 1,639,733.59/1,405.38
6. Step 6: Final answer
   x = 1,166.75