Finding the Fourth Proportional to 1,441.21, 1,988.67 and 811.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,441.21 : 1,988.67 = 811.63 : x
2. Step 2: Convert to fraction form
   1,441.21/1,988.67 = 811.63/x
3. Step 3: Cross multiply
   1,441.21x = 1,988.67 × 811.63
4. Step 4: Simplify right side
   1,441.21x = 1,614,064.23
5. Step 5: Solve for x
   x = 1,614,064.23/1,441.21
6. Step 6: Final answer
   x = 1,119.94