Finding the Fourth Proportional to 1,567.71, 2,163.59 and 978.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,567.71 : 2,163.59 = 978.30 : x
2. Step 2: Convert to fraction form
   1,567.71/2,163.59 = 978.30/x
3. Step 3: Cross multiply
   1,567.71x = 2,163.59 × 978.30
4. Step 4: Simplify right side
   1,567.71x = 2,116,635.21
5. Step 5: Solve for x
   x = 2,116,635.21/1,567.71
6. Step 6: Final answer
   x = 1,350.14