Finding the Fourth Proportional to 1,434.24, 1,979.28 and 813.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,434.24 : 1,979.28 = 813.12 : x
2. Step 2: Convert to fraction form
   1,434.24/1,979.28 = 813.12/x
3. Step 3: Cross multiply
   1,434.24x = 1,979.28 × 813.12
4. Step 4: Simplify right side
   1,434.24x = 1,609,392.15
5. Step 5: Solve for x
   x = 1,609,392.15/1,434.24
6. Step 6: Final answer
   x = 1,122.12