Finding the Fourth Proportional to 2,166.15, 2,988.10 and 1,281.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,166.15 : 2,988.10 = 1,281.78 : x
2. Step 2: Convert to fraction form
   2,166.15/2,988.10 = 1,281.78/x
3. Step 3: Cross multiply
   2,166.15x = 2,988.10 × 1,281.78
4. Step 4: Simplify right side
   2,166.15x = 3,830,086.82
5. Step 5: Solve for x
   x = 3,830,086.82/2,166.15
6. Step 6: Final answer
   x = 1,768.15