Finding the Fourth Proportional to 1,018.86, 1,402.44 and 900.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,018.86 : 1,402.44 = 900.42 : x
2. Step 2: Convert to fraction form
   1,018.86/1,402.44 = 900.42/x
3. Step 3: Cross multiply
   1,018.86x = 1,402.44 × 900.42
4. Step 4: Simplify right side
   1,018.86x = 1,262,785.02
5. Step 5: Solve for x
   x = 1,262,785.02/1,018.86
6. Step 6: Final answer
   x = 1,239.41