Finding the Fourth Proportional to 1,308.81, 1,961.89 and 578.26

Step by Step Solution

1. Step 1: Write the proportion equation
   1,308.81 : 1,961.89 = 578.26 : x
2. Step 2: Convert to fraction form
   1,308.81/1,961.89 = 578.26/x
3. Step 3: Cross multiply
   1,308.81x = 1,961.89 × 578.26
4. Step 4: Simplify right side
   1,308.81x = 1,134,482.51
5. Step 5: Solve for x
   x = 1,134,482.51/1,308.81
6. Step 6: Final answer
   x = 866.80