Finding the Fourth Proportional to 1,419.80, 1,959.20 and 830.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,419.80 : 1,959.20 = 830.28 : x
2. Step 2: Convert to fraction form
   1,419.80/1,959.20 = 830.28/x
3. Step 3: Cross multiply
   1,419.80x = 1,959.20 × 830.28
4. Step 4: Simplify right side
   1,419.80x = 1,626,684.58
5. Step 5: Solve for x
   x = 1,626,684.58/1,419.80
6. Step 6: Final answer
   x = 1,145.71