Finding the Fourth Proportional to 1,511.51, 2,085.39 and 980.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,511.51 : 2,085.39 = 980.81 : x
2. Step 2: Convert to fraction form
   1,511.51/2,085.39 = 980.81/x
3. Step 3: Cross multiply
   1,511.51x = 2,085.39 × 980.81
4. Step 4: Simplify right side
   1,511.51x = 2,045,371.37
5. Step 5: Solve for x
   x = 2,045,371.37/1,511.51
6. Step 6: Final answer
   x = 1,353.20