Finding the Fourth Proportional to 1,018.76, 1,406.12 and 646.26

Step by Step Solution

1. Step 1: Write the proportion equation
   1,018.76 : 1,406.12 = 646.26 : x
2. Step 2: Convert to fraction form
   1,018.76/1,406.12 = 646.26/x
3. Step 3: Cross multiply
   1,018.76x = 1,406.12 × 646.26
4. Step 4: Simplify right side
   1,018.76x = 908,719.11
5. Step 5: Solve for x
   x = 908,719.11/1,018.76
6. Step 6: Final answer
   x = 891.99