Finding the Fourth Proportional to 1,317.30, 1,977.78 and 668.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,317.30 : 1,977.78 = 668.50 : x
2. Step 2: Convert to fraction form
   1,317.30/1,977.78 = 668.50/x
3. Step 3: Cross multiply
   1,317.30x = 1,977.78 × 668.50
4. Step 4: Simplify right side
   1,317.30x = 1,322,145.93
5. Step 5: Solve for x
   x = 1,322,145.93/1,317.30
6. Step 6: Final answer
   x = 1,003.68