Finding the Fourth Proportional to 1,323.98, 1,985.55 and 915.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,323.98 : 1,985.55 = 915.74 : x
2. Step 2: Convert to fraction form
   1,323.98/1,985.55 = 915.74/x
3. Step 3: Cross multiply
   1,323.98x = 1,985.55 × 915.74
4. Step 4: Simplify right side
   1,323.98x = 1,818,247.56
5. Step 5: Solve for x
   x = 1,818,247.56/1,323.98
6. Step 6: Final answer
   x = 1,373.32