Finding the Fourth Proportional to 2,113.77, 2,917.72 and 1,230.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,113.77 : 2,917.72 = 1,230.31 : x
2. Step 2: Convert to fraction form
   2,113.77/2,917.72 = 1,230.31/x
3. Step 3: Cross multiply
   2,113.77x = 2,917.72 × 1,230.31
4. Step 4: Simplify right side
   2,113.77x = 3,589,693.94
5. Step 5: Solve for x
   x = 3,589,693.94/2,113.77
6. Step 6: Final answer
   x = 1,698.25