Finding the Fourth Proportional to 1,258.72, 1,887.78 and 528.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,258.72 : 1,887.78 = 528.31 : x
2. Step 2: Convert to fraction form
   1,258.72/1,887.78 = 528.31/x
3. Step 3: Cross multiply
   1,258.72x = 1,887.78 × 528.31
4. Step 4: Simplify right side
   1,258.72x = 997,333.05
5. Step 5: Solve for x
   x = 997,333.05/1,258.72
6. Step 6: Final answer
   x = 792.34