Finding the Fourth Proportional to 1,015.89, 1,401.35 and 661.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,015.89 : 1,401.35 = 661.87 : x
2. Step 2: Convert to fraction form
   1,015.89/1,401.35 = 661.87/x
3. Step 3: Cross multiply
   1,015.89x = 1,401.35 × 661.87
4. Step 4: Simplify right side
   1,015.89x = 927,513.69
5. Step 5: Solve for x
   x = 927,513.69/1,015.89
6. Step 6: Final answer
   x = 913.00