Finding the Fourth Proportional to 2,145.93, 3,219.24 and 830.28

Step by Step Solution

1. Step 1: Write the proportion equation
   2,145.93 : 3,219.24 = 830.28 : x
2. Step 2: Convert to fraction form
   2,145.93/3,219.24 = 830.28/x
3. Step 3: Cross multiply
   2,145.93x = 3,219.24 × 830.28
4. Step 4: Simplify right side
   2,145.93x = 2,672,870.59
5. Step 5: Solve for x
   x = 2,672,870.59/2,145.93
6. Step 6: Final answer
   x = 1,245.55