Finding the Fourth Proportional to 933.72, 1,398.42 and 918.72

Step by Step Solution

1. Step 1: Write the proportion equation
   933.72 : 1,398.42 = 918.72 : x
2. Step 2: Convert to fraction form
   933.72/1,398.42 = 918.72/x
3. Step 3: Cross multiply
   933.72x = 1,398.42 × 918.72
4. Step 4: Simplify right side
   933.72x = 1,284,756.42
5. Step 5: Solve for x
   x = 1,284,756.42/933.72
6. Step 6: Final answer
   x = 1,375.95