Finding the Fourth Proportional to 3,645.32, 5,031.53 and 2,153.78

Step by Step Solution

1. Step 1: Write the proportion equation
   3,645.32 : 5,031.53 = 2,153.78 : x
2. Step 2: Convert to fraction form
   3,645.32/5,031.53 = 2,153.78/x
3. Step 3: Cross multiply
   3,645.32x = 5,031.53 × 2,153.78
4. Step 4: Simplify right side
   3,645.32x = 10,836,772.76
5. Step 5: Solve for x
   x = 10,836,772.76/3,645.32
6. Step 6: Final answer
   x = 2,972.79