Finding the Fourth Proportional to 1,880.42, 2,821.43 and 840.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,880.42 : 2,821.43 = 840.38 : x
2. Step 2: Convert to fraction form
   1,880.42/2,821.43 = 840.38/x
3. Step 3: Cross multiply
   1,880.42x = 2,821.43 × 840.38
4. Step 4: Simplify right side
   1,880.42x = 2,371,061.34
5. Step 5: Solve for x
   x = 2,371,061.34/1,880.42
6. Step 6: Final answer
   x = 1,260.92