Finding the Fourth Proportional to 1,047.60, 1,445.28 and 786.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,047.60 : 1,445.28 = 786.72 : x
2. Step 2: Convert to fraction form
   1,047.60/1,445.28 = 786.72/x
3. Step 3: Cross multiply
   1,047.60x = 1,445.28 × 786.72
4. Step 4: Simplify right side
   1,047.60x = 1,137,030.68
5. Step 5: Solve for x
   x = 1,137,030.68/1,047.60
6. Step 6: Final answer
   x = 1,085.37