Finding the Fourth Proportional to 1,222.34, 1,686.12 and 779.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.34 : 1,686.12 = 779.46 : x
2. Step 2: Convert to fraction form
   1,222.34/1,686.12 = 779.46/x
3. Step 3: Cross multiply
   1,222.34x = 1,686.12 × 779.46
4. Step 4: Simplify right side
   1,222.34x = 1,314,263.10
5. Step 5: Solve for x
   x = 1,314,263.10/1,222.34
6. Step 6: Final answer
   x = 1,075.21