Finding the Fourth Proportional to 985.72, 1,475.34 and 877.72

Step by Step Solution

1. Step 1: Write the proportion equation
   985.72 : 1,475.34 = 877.72 : x
2. Step 2: Convert to fraction form
   985.72/1,475.34 = 877.72/x
3. Step 3: Cross multiply
   985.72x = 1,475.34 × 877.72
4. Step 4: Simplify right side
   985.72x = 1,294,935.42
5. Step 5: Solve for x
   x = 1,294,935.42/985.72
6. Step 6: Final answer
   x = 1,313.69