Finding the Fourth Proportional to 1,258.72, 1,888.89 and 478.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,258.72 : 1,888.89 = 478.72 : x
2. Step 2: Convert to fraction form
   1,258.72/1,888.89 = 478.72/x
3. Step 3: Cross multiply
   1,258.72x = 1,888.89 × 478.72
4. Step 4: Simplify right side
   1,258.72x = 904,249.42
5. Step 5: Solve for x
   x = 904,249.42/1,258.72
6. Step 6: Final answer
   x = 718.39