Finding the Fourth Proportional to 1,191.72, 1,787.31 and 326.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.72 : 1,787.31 = 326.10 : x
2. Step 2: Convert to fraction form
   1,191.72/1,787.31 = 326.10/x
3. Step 3: Cross multiply
   1,191.72x = 1,787.31 × 326.10
4. Step 4: Simplify right side
   1,191.72x = 582,841.79
5. Step 5: Solve for x
   x = 582,841.79/1,191.72
6. Step 6: Final answer
   x = 489.08