Finding the Fourth Proportional to 2,166.72, 2,988.72 and 1,420.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,166.72 : 2,988.72 = 1,420.72 : x
2. Step 2: Convert to fraction form
   2,166.72/2,988.72 = 1,420.72/x
3. Step 3: Cross multiply
   2,166.72x = 2,988.72 × 1,420.72
4. Step 4: Simplify right side
   2,166.72x = 4,246,134.28
5. Step 5: Solve for x
   x = 4,246,134.28/2,166.72
6. Step 6: Final answer
   x = 1,959.71