Finding the Fourth Proportional to 1,985.81, 2,965.35 and 1,621.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,985.81 : 2,965.35 = 1,621.31 : x
2. Step 2: Convert to fraction form
   1,985.81/2,965.35 = 1,621.31/x
3. Step 3: Cross multiply
   1,985.81x = 2,965.35 × 1,621.31
4. Step 4: Simplify right side
   1,985.81x = 4,807,743.50
5. Step 5: Solve for x
   x = 4,807,743.50/1,985.81
6. Step 6: Final answer
   x = 2,421.05