Finding the Fourth Proportional to 1,284.56, 1,772.25 and 842.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,284.56 : 1,772.25 = 842.72 : x
2. Step 2: Convert to fraction form
   1,284.56/1,772.25 = 842.72/x
3. Step 3: Cross multiply
   1,284.56x = 1,772.25 × 842.72
4. Step 4: Simplify right side
   1,284.56x = 1,493,510.52
5. Step 5: Solve for x
   x = 1,493,510.52/1,284.56
6. Step 6: Final answer
   x = 1,162.66