Finding the Fourth Proportional to 1,072.56, 1,478.88 and 994.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,072.56 : 1,478.88 = 994.80 : x
2. Step 2: Convert to fraction form
   1,072.56/1,478.88 = 994.80/x
3. Step 3: Cross multiply
   1,072.56x = 1,478.88 × 994.80
4. Step 4: Simplify right side
   1,072.56x = 1,471,189.82
5. Step 5: Solve for x
   x = 1,471,189.82/1,072.56
6. Step 6: Final answer
   x = 1,371.66