Finding the Fourth Proportional to 2,145.67, 3,221.43 and 1,106.53

Step by Step Solution

1. Step 1: Write the proportion equation
   2,145.67 : 3,221.43 = 1,106.53 : x
2. Step 2: Convert to fraction form
   2,145.67/3,221.43 = 1,106.53/x
3. Step 3: Cross multiply
   2,145.67x = 3,221.43 × 1,106.53
4. Step 4: Simplify right side
   2,145.67x = 3,564,608.94
5. Step 5: Solve for x
   x = 3,564,608.94/2,145.67
6. Step 6: Final answer
   x = 1,661.30