Finding the Fourth Proportional to 1,089.35, 1,502.28 and 840.27

Step by Step Solution

1. Step 1: Write the proportion equation
   1,089.35 : 1,502.28 = 840.27 : x
2. Step 2: Convert to fraction form
   1,089.35/1,502.28 = 840.27/x
3. Step 3: Cross multiply
   1,089.35x = 1,502.28 × 840.27
4. Step 4: Simplify right side
   1,089.35x = 1,262,316.61
5. Step 5: Solve for x
   x = 1,262,316.61/1,089.35
6. Step 6: Final answer
   x = 1,158.78