Finding the Fourth Proportional to 3,918.51, 5,878.69 and 1,286.15

Step by Step Solution

1. Step 1: Write the proportion equation
   3,918.51 : 5,878.69 = 1,286.15 : x
2. Step 2: Convert to fraction form
   3,918.51/5,878.69 = 1,286.15/x
3. Step 3: Cross multiply
   3,918.51x = 5,878.69 × 1,286.15
4. Step 4: Simplify right side
   3,918.51x = 7,560,844.53
5. Step 5: Solve for x
   x = 7,560,844.53/3,918.51
6. Step 6: Final answer
   x = 1,929.52