Finding the Fourth Proportional to 2,145.38, 3,215.93 and 1,913.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,145.38 : 3,215.93 = 1,913.31 : x
2. Step 2: Convert to fraction form
   2,145.38/3,215.93 = 1,913.31/x
3. Step 3: Cross multiply
   2,145.38x = 3,215.93 × 1,913.31
4. Step 4: Simplify right side
   2,145.38x = 6,153,061.46
5. Step 5: Solve for x
   x = 6,153,061.46/2,145.38
6. Step 6: Final answer
   x = 2,868.06