Finding the Fourth Proportional to 1,120.98, 1,547.10 and 678.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,120.98 : 1,547.10 = 678.89 : x
2. Step 2: Convert to fraction form
   1,120.98/1,547.10 = 678.89/x
3. Step 3: Cross multiply
   1,120.98x = 1,547.10 × 678.89
4. Step 4: Simplify right side
   1,120.98x = 1,050,310.72
5. Step 5: Solve for x
   x = 1,050,310.72/1,120.98
6. Step 6: Final answer
   x = 936.96