Finding the Fourth Proportional to 2,166.72, 2,989.62 and 1,379.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,166.72 : 2,989.62 = 1,379.40 : x
2. Step 2: Convert to fraction form
   2,166.72/2,989.62 = 1,379.40/x
3. Step 3: Cross multiply
   2,166.72x = 2,989.62 × 1,379.40
4. Step 4: Simplify right side
   2,166.72x = 4,123,881.83
5. Step 5: Solve for x
   x = 4,123,881.83/2,166.72
6. Step 6: Final answer
   x = 1,903.28