Finding the Fourth Proportional to 2,115.78, 3,174.34 and 1,020.22

Step by Step Solution

1. Step 1: Write the proportion equation
   2,115.78 : 3,174.34 = 1,020.22 : x
2. Step 2: Convert to fraction form
   2,115.78/3,174.34 = 1,020.22/x
3. Step 3: Cross multiply
   2,115.78x = 3,174.34 × 1,020.22
4. Step 4: Simplify right side
   2,115.78x = 3,238,525.15
5. Step 5: Solve for x
   x = 3,238,525.15/2,115.78
6. Step 6: Final answer
   x = 1,530.65