Finding the Fourth Proportional to 2,311.56, 3,189.75 and 1,316.88

Step by Step Solution

1. Step 1: Write the proportion equation
   2,311.56 : 3,189.75 = 1,316.88 : x
2. Step 2: Convert to fraction form
   2,311.56/3,189.75 = 1,316.88/x
3. Step 3: Cross multiply
   2,311.56x = 3,189.75 × 1,316.88
4. Step 4: Simplify right side
   2,311.56x = 4,200,517.98
5. Step 5: Solve for x
   x = 4,200,517.98/2,311.56
6. Step 6: Final answer
   x = 1,817.18