Finding the Fourth Proportional to 2,145.72, 2,961.30 and 1,261.32

Step by Step Solution

1. Step 1: Write the proportion equation
   2,145.72 : 2,961.30 = 1,261.32 : x
2. Step 2: Convert to fraction form
   2,145.72/2,961.30 = 1,261.32/x
3. Step 3: Cross multiply
   2,145.72x = 2,961.30 × 1,261.32
4. Step 4: Simplify right side
   2,145.72x = 3,735,146.92
5. Step 5: Solve for x
   x = 3,735,146.92/2,145.72
6. Step 6: Final answer
   x = 1,740.74