Finding the Fourth Proportional to 1,090.42, 1,631.86 and 673.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,090.42 : 1,631.86 = 673.78 : x
2. Step 2: Convert to fraction form
   1,090.42/1,631.86 = 673.78/x
3. Step 3: Cross multiply
   1,090.42x = 1,631.86 × 673.78
4. Step 4: Simplify right side
   1,090.42x = 1,099,514.63
5. Step 5: Solve for x
   x = 1,099,514.63/1,090.42
6. Step 6: Final answer
   x = 1,008.34