Finding the Fourth Proportional to 1,016.66, 1,402.47 and 643.01

Step by Step Solution

1. Step 1: Write the proportion equation
   1,016.66 : 1,402.47 = 643.01 : x
2. Step 2: Convert to fraction form
   1,016.66/1,402.47 = 643.01/x
3. Step 3: Cross multiply
   1,016.66x = 1,402.47 × 643.01
4. Step 4: Simplify right side
   1,016.66x = 901,795.22
5. Step 5: Solve for x
   x = 901,795.22/1,016.66
6. Step 6: Final answer
   x = 887.02