Finding the Fourth Proportional to 1,057.30, 1,585.58 and 316.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,057.30 : 1,585.58 = 316.69 : x
2. Step 2: Convert to fraction form
   1,057.30/1,585.58 = 316.69/x
3. Step 3: Cross multiply
   1,057.30x = 1,585.58 × 316.69
4. Step 4: Simplify right side
   1,057.30x = 502,131.78
5. Step 5: Solve for x
   x = 502,131.78/1,057.30
6. Step 6: Final answer
   x = 474.92