Finding the Fourth Proportional to 1,369.20, 1,888.71 and 779.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,369.20 : 1,888.71 = 779.63 : x
2. Step 2: Convert to fraction form
   1,369.20/1,888.71 = 779.63/x
3. Step 3: Cross multiply
   1,369.20x = 1,888.71 × 779.63
4. Step 4: Simplify right side
   1,369.20x = 1,472,485.53
5. Step 5: Solve for x
   x = 1,472,485.53/1,369.20
6. Step 6: Final answer
   x = 1,075.43