Finding the Fourth Proportional to 1,345.07, 1,855.05 and 1,215.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,345.07 : 1,855.05 = 1,215.47 : x
2. Step 2: Convert to fraction form
   1,345.07/1,855.05 = 1,215.47/x
3. Step 3: Cross multiply
   1,345.07x = 1,855.05 × 1,215.47
4. Step 4: Simplify right side
   1,345.07x = 2,254,757.62
5. Step 5: Solve for x
   x = 2,254,757.62/1,345.07
6. Step 6: Final answer
   x = 1,676.31