Finding the Fourth Proportional to 1,213.61, 1,815.56 and 1,064.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,213.61 : 1,815.56 = 1,064.57 : x
2. Step 2: Convert to fraction form
   1,213.61/1,815.56 = 1,064.57/x
3. Step 3: Cross multiply
   1,213.61x = 1,815.56 × 1,064.57
4. Step 4: Simplify right side
   1,213.61x = 1,932,785.39
5. Step 5: Solve for x
   x = 1,932,785.39/1,213.61
6. Step 6: Final answer
   x = 1,592.59