Finding the Fourth Proportional to 1,528.69, 2,109.72 and 939.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,528.69 : 2,109.72 = 939.43 : x
2. Step 2: Convert to fraction form
   1,528.69/2,109.72 = 939.43/x
3. Step 3: Cross multiply
   1,528.69x = 2,109.72 × 939.43
4. Step 4: Simplify right side
   1,528.69x = 1,981,934.26
5. Step 5: Solve for x
   x = 1,981,934.26/1,528.69
6. Step 6: Final answer
   x = 1,296.49