Finding the Fourth Proportional to 1,142.42, 1,576.54 and 645.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,142.42 : 1,576.54 = 645.06 : x
2. Step 2: Convert to fraction form
   1,142.42/1,576.54 = 645.06/x
3. Step 3: Cross multiply
   1,142.42x = 1,576.54 × 645.06
4. Step 4: Simplify right side
   1,142.42x = 1,016,962.89
5. Step 5: Solve for x
   x = 1,016,962.89/1,142.42
6. Step 6: Final answer
   x = 890.18