Finding the Fourth Proportional to 931.27, 1,404.30 and 918.91

Step by Step Solution

1. Step 1: Write the proportion equation
   931.27 : 1,404.30 = 918.91 : x
2. Step 2: Convert to fraction form
   931.27/1,404.30 = 918.91/x
3. Step 3: Cross multiply
   931.27x = 1,404.30 × 918.91
4. Step 4: Simplify right side
   931.27x = 1,290,425.31
5. Step 5: Solve for x
   x = 1,290,425.31/931.27
6. Step 6: Final answer
   x = 1,385.66