Finding the Fourth Proportional to 1,379.22, 2,058.72 and 1,215.19

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.22 : 2,058.72 = 1,215.19 : x
2. Step 2: Convert to fraction form
   1,379.22/2,058.72 = 1,215.19/x
3. Step 3: Cross multiply
   1,379.22x = 2,058.72 × 1,215.19
4. Step 4: Simplify right side
   1,379.22x = 2,501,735.96
5. Step 5: Solve for x
   x = 2,501,735.96/1,379.22
6. Step 6: Final answer
   x = 1,813.88