Finding the Fourth Proportional to 900.42, 1,243.47 and 715.86

Step by Step Solution

1. Step 1: Write the proportion equation
   900.42 : 1,243.47 = 715.86 : x
2. Step 2: Convert to fraction form
   900.42/1,243.47 = 715.86/x
3. Step 3: Cross multiply
   900.42x = 1,243.47 × 715.86
4. Step 4: Simplify right side
   900.42x = 890,150.43
5. Step 5: Solve for x
   x = 890,150.43/900.42
6. Step 6: Final answer
   x = 988.59