Finding the Fourth Proportional to 1,401.45, 2,101.47 and 816.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,401.45 : 2,101.47 = 816.64 : x
2. Step 2: Convert to fraction form
   1,401.45/2,101.47 = 816.64/x
3. Step 3: Cross multiply
   1,401.45x = 2,101.47 × 816.64
4. Step 4: Simplify right side
   1,401.45x = 1,716,144.46
5. Step 5: Solve for x
   x = 1,716,144.46/1,401.45
6. Step 6: Final answer
   x = 1,224.55