Finding the Fourth Proportional to 1,635.89, 2,257.42 and 972.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,635.89 : 2,257.42 = 972.80 : x
2. Step 2: Convert to fraction form
   1,635.89/2,257.42 = 972.80/x
3. Step 3: Cross multiply
   1,635.89x = 2,257.42 × 972.80
4. Step 4: Simplify right side
   1,635.89x = 2,196,018.18
5. Step 5: Solve for x
   x = 2,196,018.18/1,635.89
6. Step 6: Final answer
   x = 1,342.40