Finding the Fourth Proportional to 1,443.22, 1,991.69 and 853.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.22 : 1,991.69 = 853.74 : x
2. Step 2: Convert to fraction form
   1,443.22/1,991.69 = 853.74/x
3. Step 3: Cross multiply
   1,443.22x = 1,991.69 × 853.74
4. Step 4: Simplify right side
   1,443.22x = 1,700,384.35
5. Step 5: Solve for x
   x = 1,700,384.35/1,443.22
6. Step 6: Final answer
   x = 1,178.19