Finding the Fourth Proportional to 1,101.78, 1,651.05 and 667.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,101.78 : 1,651.05 = 667.89 : x
2. Step 2: Convert to fraction form
   1,101.78/1,651.05 = 667.89/x
3. Step 3: Cross multiply
   1,101.78x = 1,651.05 × 667.89
4. Step 4: Simplify right side
   1,101.78x = 1,102,719.78
5. Step 5: Solve for x
   x = 1,102,719.78/1,101.78
6. Step 6: Final answer
   x = 1,000.85