Finding the Fourth Proportional to 1,008.59, 1,513.49 and 521.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,008.59 : 1,513.49 = 521.64 : x
2. Step 2: Convert to fraction form
   1,008.59/1,513.49 = 521.64/x
3. Step 3: Cross multiply
   1,008.59x = 1,513.49 × 521.64
4. Step 4: Simplify right side
   1,008.59x = 789,494.32
5. Step 5: Solve for x
   x = 789,494.32/1,008.59
6. Step 6: Final answer
   x = 782.77