Finding the Fourth Proportional to 1,016.19, 1,401.80 and 643.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,016.19 : 1,401.80 = 643.04 : x
2. Step 2: Convert to fraction form
   1,016.19/1,401.80 = 643.04/x
3. Step 3: Cross multiply
   1,016.19x = 1,401.80 × 643.04
4. Step 4: Simplify right side
   1,016.19x = 901,406.46
5. Step 5: Solve for x
   x = 901,406.46/1,016.19
6. Step 6: Final answer
   x = 887.05