Finding the Fourth Proportional to 3,994.59, 5,991.90 and 1,221.25

Step by Step Solution

1. Step 1: Write the proportion equation
   3,994.59 : 5,991.90 = 1,221.25 : x
2. Step 2: Convert to fraction form
   3,994.59/5,991.90 = 1,221.25/x
3. Step 3: Cross multiply
   3,994.59x = 5,991.90 × 1,221.25
4. Step 4: Simplify right side
   3,994.59x = 7,317,599.55
5. Step 5: Solve for x
   x = 7,317,599.55/3,994.59
6. Step 6: Final answer
   x = 1,831.88