Finding the Fourth Proportional to 1,015.42, 1,400.56 and 779.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,015.42 : 1,400.56 = 779.40 : x
2. Step 2: Convert to fraction form
   1,015.42/1,400.56 = 779.40/x
3. Step 3: Cross multiply
   1,015.42x = 1,400.56 × 779.40
4. Step 4: Simplify right side
   1,015.42x = 1,091,596.46
5. Step 5: Solve for x
   x = 1,091,596.46/1,015.42
6. Step 6: Final answer
   x = 1,075.02