Finding the Fourth Proportional to 1,171.82, 1,757.69 and 391.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,171.82 : 1,757.69 = 391.88 : x
2. Step 2: Convert to fraction form
   1,171.82/1,757.69 = 391.88/x
3. Step 3: Cross multiply
   1,171.82x = 1,757.69 × 391.88
4. Step 4: Simplify right side
   1,171.82x = 688,803.56
5. Step 5: Solve for x
   x = 688,803.56/1,171.82
6. Step 6: Final answer
   x = 587.81