Finding the Fourth Proportional to 1,090.72, 1,503.12 and 779.68

Step by Step Solution

1. Step 1: Write the proportion equation
   1,090.72 : 1,503.12 = 779.68 : x
2. Step 2: Convert to fraction form
   1,090.72/1,503.12 = 779.68/x
3. Step 3: Cross multiply
   1,090.72x = 1,503.12 × 779.68
4. Step 4: Simplify right side
   1,090.72x = 1,171,952.60
5. Step 5: Solve for x
   x = 1,171,952.60/1,090.72
6. Step 6: Final answer
   x = 1,074.48