Finding the Fourth Proportional to 1,310.76, 1,810.01 and 978.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,310.76 : 1,810.01 = 978.61 : x
2. Step 2: Convert to fraction form
   1,310.76/1,810.01 = 978.61/x
3. Step 3: Cross multiply
   1,310.76x = 1,810.01 × 978.61
4. Step 4: Simplify right side
   1,310.76x = 1,771,293.89
5. Step 5: Solve for x
   x = 1,771,293.89/1,310.76
6. Step 6: Final answer
   x = 1,351.35