Finding the Fourth Proportional to 1,142.53, 1,576.69 and 645.14

Step by Step Solution

1. Step 1: Write the proportion equation
   1,142.53 : 1,576.69 = 645.14 : x
2. Step 2: Convert to fraction form
   1,142.53/1,576.69 = 645.14/x
3. Step 3: Cross multiply
   1,142.53x = 1,576.69 × 645.14
4. Step 4: Simplify right side
   1,142.53x = 1,017,188.12
5. Step 5: Solve for x
   x = 1,017,188.12/1,142.53
6. Step 6: Final answer
   x = 890.30