Finding the Fourth Proportional to 2,145.87, 3,216.37 and 912.51

Step by Step Solution

1. Step 1: Write the proportion equation
   2,145.87 : 3,216.37 = 912.51 : x
2. Step 2: Convert to fraction form
   2,145.87/3,216.37 = 912.51/x
3. Step 3: Cross multiply
   2,145.87x = 3,216.37 × 912.51
4. Step 4: Simplify right side
   2,145.87x = 2,934,969.79
5. Step 5: Solve for x
   x = 2,934,969.79/2,145.87
6. Step 6: Final answer
   x = 1,367.73