Finding the Fourth Proportional to 1,086.34, 1,628.28 and 538.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.34 : 1,628.28 = 538.91 : x
2. Step 2: Convert to fraction form
   1,086.34/1,628.28 = 538.91/x
3. Step 3: Cross multiply
   1,086.34x = 1,628.28 × 538.91
4. Step 4: Simplify right side
   1,086.34x = 877,496.37
5. Step 5: Solve for x
   x = 877,496.37/1,086.34
6. Step 6: Final answer
   x = 807.76