Finding the Fourth Proportional to 1,016.17, 1,401.68 and 642.51

Step by Step Solution

1. Step 1: Write the proportion equation
   1,016.17 : 1,401.68 = 642.51 : x
2. Step 2: Convert to fraction form
   1,016.17/1,401.68 = 642.51/x
3. Step 3: Cross multiply
   1,016.17x = 1,401.68 × 642.51
4. Step 4: Simplify right side
   1,016.17x = 900,595.02
5. Step 5: Solve for x
   x = 900,595.02/1,016.17
6. Step 6: Final answer
   x = 886.27