Finding the Fourth Proportional to 1,016.94, 1,402.42 and 643.29

Step by Step Solution

1. Step 1: Write the proportion equation
   1,016.94 : 1,402.42 = 643.29 : x
2. Step 2: Convert to fraction form
   1,016.94/1,402.42 = 643.29/x
3. Step 3: Cross multiply
   1,016.94x = 1,402.42 × 643.29
4. Step 4: Simplify right side
   1,016.94x = 902,162.76
5. Step 5: Solve for x
   x = 902,162.76/1,016.94
6. Step 6: Final answer
   x = 887.13