Finding the Fourth Proportional to 1,238.34, 1,855.78 and 579.51

Step by Step Solution

1. Step 1: Write the proportion equation
   1,238.34 : 1,855.78 = 579.51 : x
2. Step 2: Convert to fraction form
   1,238.34/1,855.78 = 579.51/x
3. Step 3: Cross multiply
   1,238.34x = 1,855.78 × 579.51
4. Step 4: Simplify right side
   1,238.34x = 1,075,441.62
5. Step 5: Solve for x
   x = 1,075,441.62/1,238.34
6. Step 6: Final answer
   x = 868.45