Finding the Fourth Proportional to 1,201.98, 1,658.88 and 678.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,201.98 : 1,658.88 = 678.10 : x
2. Step 2: Convert to fraction form
   1,201.98/1,658.88 = 678.10/x
3. Step 3: Cross multiply
   1,201.98x = 1,658.88 × 678.10
4. Step 4: Simplify right side
   1,201.98x = 1,124,886.53
5. Step 5: Solve for x
   x = 1,124,886.53/1,201.98
6. Step 6: Final answer
   x = 935.86