Finding the Fourth Proportional to 1,146.15, 1,578.09 and 1,011.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,146.15 : 1,578.09 = 1,011.42 : x
2. Step 2: Convert to fraction form
   1,146.15/1,578.09 = 1,011.42/x
3. Step 3: Cross multiply
   1,146.15x = 1,578.09 × 1,011.42
4. Step 4: Simplify right side
   1,146.15x = 1,596,111.79
5. Step 5: Solve for x
   x = 1,596,111.79/1,146.15
6. Step 6: Final answer
   x = 1,392.59