Finding the Fourth Proportional to 1,298.55, 1,790.81 and 1,015

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.55 : 1,790.81 = 1,015 : x
2. Step 2: Convert to fraction form
   1,298.55/1,790.81 = 1,015/x
3. Step 3: Cross multiply
   1,298.55x = 1,790.81 × 1,015
4. Step 4: Simplify right side
   1,298.55x = 1,817,667.08
5. Step 5: Solve for x
   x = 1,817,667.08/1,298.55
6. Step 6: Final answer
   x = 1,399.77