Finding the Fourth Proportional to 1,311.03, 1,805.72 and 978.93

Step by Step Solution

1. Step 1: Write the proportion equation
   1,311.03 : 1,805.72 = 978.93 : x
2. Step 2: Convert to fraction form
   1,311.03/1,805.72 = 978.93/x
3. Step 3: Cross multiply
   1,311.03x = 1,805.72 × 978.93
4. Step 4: Simplify right side
   1,311.03x = 1,767,668.58
5. Step 5: Solve for x
   x = 1,767,668.58/1,311.03
6. Step 6: Final answer
   x = 1,348.31