Finding the Fourth Proportional to 2,145.16, 3,216.91 and 913.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,145.16 : 3,216.91 = 913.15 : x
2. Step 2: Convert to fraction form
   2,145.16/3,216.91 = 913.15/x
3. Step 3: Cross multiply
   2,145.16x = 3,216.91 × 913.15
4. Step 4: Simplify right side
   2,145.16x = 2,937,521.37
5. Step 5: Solve for x
   x = 2,937,521.37/2,145.16
6. Step 6: Final answer
   x = 1,369.37