Finding the Fourth Proportional to 2,121.24, 3,186.72 and 1,256.16

Step by Step Solution

1. Step 1: Write the proportion equation
   2,121.24 : 3,186.72 = 1,256.16 : x
2. Step 2: Convert to fraction form
   2,121.24/3,186.72 = 1,256.16/x
3. Step 3: Cross multiply
   2,121.24x = 3,186.72 × 1,256.16
4. Step 4: Simplify right side
   2,121.24x = 4,003,030.20
5. Step 5: Solve for x
   x = 4,003,030.20/2,121.24
6. Step 6: Final answer
   x = 1,887.12