Finding the Fourth Proportional to 2,128.53, 3,189.30 and 1,305.06

Step by Step Solution

1. Step 1: Write the proportion equation
   2,128.53 : 3,189.30 = 1,305.06 : x
2. Step 2: Convert to fraction form
   2,128.53/3,189.30 = 1,305.06/x
3. Step 3: Cross multiply
   2,128.53x = 3,189.30 × 1,305.06
4. Step 4: Simplify right side
   2,128.53x = 4,162,227.86
5. Step 5: Solve for x
   x = 4,162,227.86/2,128.53
6. Step 6: Final answer
   x = 1,955.45