Finding the Fourth Proportional to 2,115.18, 2,918.89 and 1,158.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,115.18 : 2,918.89 = 1,158.05 : x
2. Step 2: Convert to fraction form
   2,115.18/2,918.89 = 1,158.05/x
3. Step 3: Cross multiply
   2,115.18x = 2,918.89 × 1,158.05
4. Step 4: Simplify right side
   2,115.18x = 3,380,220.56
5. Step 5: Solve for x
   x = 3,380,220.56/2,115.18
6. Step 6: Final answer
   x = 1,598.08