Finding the Fourth Proportional to 1,429.42, 2,142.40 and 811.84

Step by Step Solution

1. Step 1: Write the proportion equation
   1,429.42 : 2,142.40 = 811.84 : x
2. Step 2: Convert to fraction form
   1,429.42/2,142.40 = 811.84/x
3. Step 3: Cross multiply
   1,429.42x = 2,142.40 × 811.84
4. Step 4: Simplify right side
   1,429.42x = 1,739,286.02
5. Step 5: Solve for x
   x = 1,739,286.02/1,429.42
6. Step 6: Final answer
   x = 1,216.78