Finding the Fourth Proportional to 1,322.21, 1,823.15 and 989.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,322.21 : 1,823.15 = 989.57 : x
2. Step 2: Convert to fraction form
   1,322.21/1,823.15 = 989.57/x
3. Step 3: Cross multiply
   1,322.21x = 1,823.15 × 989.57
4. Step 4: Simplify right side
   1,322.21x = 1,804,134.55
5. Step 5: Solve for x
   x = 1,804,134.55/1,322.21
6. Step 6: Final answer
   x = 1,364.48