Finding the Fourth Proportional to 1,538.56, 2,122.56 and 978.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,538.56 : 2,122.56 = 978.72 : x
2. Step 2: Convert to fraction form
   1,538.56/2,122.56 = 978.72/x
3. Step 3: Cross multiply
   1,538.56x = 2,122.56 × 978.72
4. Step 4: Simplify right side
   1,538.56x = 2,077,391.92
5. Step 5: Solve for x
   x = 2,077,391.92/1,538.56
6. Step 6: Final answer
   x = 1,350.22