Finding the Fourth Proportional to 1,651.72, 2,479.40 and 678.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,651.72 : 2,479.40 = 678.50 : x
2. Step 2: Convert to fraction form
   1,651.72/2,479.40 = 678.50/x
3. Step 3: Cross multiply
   1,651.72x = 2,479.40 × 678.50
4. Step 4: Simplify right side
   1,651.72x = 1,682,272.90
5. Step 5: Solve for x
   x = 1,682,272.90/1,651.72
6. Step 6: Final answer
   x = 1,018.50