Finding the Fourth Proportional to 1,338.71, 1,846.54 and 840.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,338.71 : 1,846.54 = 840.90 : x
2. Step 2: Convert to fraction form
   1,338.71/1,846.54 = 840.90/x
3. Step 3: Cross multiply
   1,338.71x = 1,846.54 × 840.90
4. Step 4: Simplify right side
   1,338.71x = 1,552,763.46
5. Step 5: Solve for x
   x = 1,552,763.46/1,338.71
6. Step 6: Final answer
   x = 1,159.90