Finding the Fourth Proportional to 1,434.28, 1,978.98 and 813.16

Step by Step Solution

1. Step 1: Write the proportion equation
   1,434.28 : 1,978.98 = 813.16 : x
2. Step 2: Convert to fraction form
   1,434.28/1,978.98 = 813.16/x
3. Step 3: Cross multiply
   1,434.28x = 1,978.98 × 813.16
4. Step 4: Simplify right side
   1,434.28x = 1,609,227.38
5. Step 5: Solve for x
   x = 1,609,227.38/1,434.28
6. Step 6: Final answer
   x = 1,121.98