Finding the Fourth Proportional to 1,528.72, 2,291.72 and 1,138.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,528.72 : 2,291.72 = 1,138.25 : x
2. Step 2: Convert to fraction form
   1,528.72/2,291.72 = 1,138.25/x
3. Step 3: Cross multiply
   1,528.72x = 2,291.72 × 1,138.25
4. Step 4: Simplify right side
   1,528.72x = 2,608,553.53
5. Step 5: Solve for x
   x = 2,608,553.53/1,528.72
6. Step 6: Final answer
   x = 1,706.36