Finding the Fourth Proportional to 1,215.78, 1,677.69 and 954.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,215.78 : 1,677.69 = 954.42 : x
2. Step 2: Convert to fraction form
   1,215.78/1,677.69 = 954.42/x
3. Step 3: Cross multiply
   1,215.78x = 1,677.69 × 954.42
4. Step 4: Simplify right side
   1,215.78x = 1,601,220.89
5. Step 5: Solve for x
   x = 1,601,220.89/1,215.78
6. Step 6: Final answer
   x = 1,317.03