Finding the Fourth Proportional to 1,536.91, 2,120.85 and 938.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,536.91 : 2,120.85 = 938.72 : x
2. Step 2: Convert to fraction form
   1,536.91/2,120.85 = 938.72/x
3. Step 3: Cross multiply
   1,536.91x = 2,120.85 × 938.72
4. Step 4: Simplify right side
   1,536.91x = 1,990,889.61
5. Step 5: Solve for x
   x = 1,990,889.61/1,536.91
6. Step 6: Final answer
   x = 1,295.39