Finding the Fourth Proportional to 1,368.72, 1,888.85 and 779.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,368.72 : 1,888.85 = 779.31 : x
2. Step 2: Convert to fraction form
   1,368.72/1,888.85 = 779.31/x
3. Step 3: Cross multiply
   1,368.72x = 1,888.85 × 779.31
4. Step 4: Simplify right side
   1,368.72x = 1,471,999.69
5. Step 5: Solve for x
   x = 1,471,999.69/1,368.72
6. Step 6: Final answer
   x = 1,075.46