Finding the Fourth Proportional to 1,019.79, 1,408.03 and 900.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.79 : 1,408.03 = 900.86 : x
2. Step 2: Convert to fraction form
   1,019.79/1,408.03 = 900.86/x
3. Step 3: Cross multiply
   1,019.79x = 1,408.03 × 900.86
4. Step 4: Simplify right side
   1,019.79x = 1,268,429.25
5. Step 5: Solve for x
   x = 1,268,429.25/1,019.79
6. Step 6: Final answer
   x = 1,243.81