Finding the Fourth Proportional to 1,379.42, 1,903.58 and 840.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.42 : 1,903.58 = 840.89 : x
2. Step 2: Convert to fraction form
   1,379.42/1,903.58 = 840.89/x
3. Step 3: Cross multiply
   1,379.42x = 1,903.58 × 840.89
4. Step 4: Simplify right side
   1,379.42x = 1,600,701.94
5. Step 5: Solve for x
   x = 1,600,701.94/1,379.42
6. Step 6: Final answer
   x = 1,160.42