Finding the Fourth Proportional to 1,458.72, 2,190.78 and 1,215.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,458.72 : 2,190.78 = 1,215.72 : x
2. Step 2: Convert to fraction form
   1,458.72/2,190.78 = 1,215.72/x
3. Step 3: Cross multiply
   1,458.72x = 2,190.78 × 1,215.72
4. Step 4: Simplify right side
   1,458.72x = 2,663,375.06
5. Step 5: Solve for x
   x = 2,663,375.06/1,458.72
6. Step 6: Final answer
   x = 1,825.83