Finding the Fourth Proportional to 1,123.08, 1,682.05 and 991.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.08 : 1,682.05 = 991.69 : x
2. Step 2: Convert to fraction form
   1,123.08/1,682.05 = 991.69/x
3. Step 3: Cross multiply
   1,123.08x = 1,682.05 × 991.69
4. Step 4: Simplify right side
   1,123.08x = 1,668,070.34
5. Step 5: Solve for x
   x = 1,668,070.34/1,123.08
6. Step 6: Final answer
   x = 1,485.27