Finding the Fourth Proportional to 1,405.31, 1,938.93 and 845.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.31 : 1,938.93 = 845.60 : x
2. Step 2: Convert to fraction form
   1,405.31/1,938.93 = 845.60/x
3. Step 3: Cross multiply
   1,405.31x = 1,938.93 × 845.60
4. Step 4: Simplify right side
   1,405.31x = 1,639,559.21
5. Step 5: Solve for x
   x = 1,639,559.21/1,405.31
6. Step 6: Final answer
   x = 1,166.69