Finding the Fourth Proportional to 1,986.45, 2,741.43 and 1,278.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,986.45 : 2,741.43 = 1,278.72 : x
2. Step 2: Convert to fraction form
   1,986.45/2,741.43 = 1,278.72/x
3. Step 3: Cross multiply
   1,986.45x = 2,741.43 × 1,278.72
4. Step 4: Simplify right side
   1,986.45x = 3,505,521.37
5. Step 5: Solve for x
   x = 3,505,521.37/1,986.45
6. Step 6: Final answer
   x = 1,764.72