Finding the Fourth Proportional to 1,321.90, 1,978.17 and 974.41

Step by Step Solution

1. Step 1: Write the proportion equation
   1,321.90 : 1,978.17 = 974.41 : x
2. Step 2: Convert to fraction form
   1,321.90/1,978.17 = 974.41/x
3. Step 3: Cross multiply
   1,321.90x = 1,978.17 × 974.41
4. Step 4: Simplify right side
   1,321.90x = 1,927,548.63
5. Step 5: Solve for x
   x = 1,927,548.63/1,321.90
6. Step 6: Final answer
   x = 1,458.17