Finding the Fourth Proportional to 1,345.05, 2,015.42 and 1,129.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,345.05 : 2,015.42 = 1,129.05 : x
2. Step 2: Convert to fraction form
   1,345.05/2,015.42 = 1,129.05/x
3. Step 3: Cross multiply
   1,345.05x = 2,015.42 × 1,129.05
4. Step 4: Simplify right side
   1,345.05x = 2,275,504.31
5. Step 5: Solve for x
   x = 2,275,504.31/1,345.05
6. Step 6: Final answer
   x = 1,691.76