Finding the Fourth Proportional to 3,765.63, 5,643.72 and 1,917.21

Step by Step Solution

1. Step 1: Write the proportion equation
   3,765.63 : 5,643.72 = 1,917.21 : x
2. Step 2: Convert to fraction form
   3,765.63/5,643.72 = 1,917.21/x
3. Step 3: Cross multiply
   3,765.63x = 5,643.72 × 1,917.21
4. Step 4: Simplify right side
   3,765.63x = 10,820,196.42
5. Step 5: Solve for x
   x = 10,820,196.42/3,765.63
6. Step 6: Final answer
   x = 2,873.41