Finding the Fourth Proportional to 1,219.32, 1,826.82 and 642.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,219.32 : 1,826.82 = 642.60 : x
2. Step 2: Convert to fraction form
   1,219.32/1,826.82 = 642.60/x
3. Step 3: Cross multiply
   1,219.32x = 1,826.82 × 642.60
4. Step 4: Simplify right side
   1,219.32x = 1,173,914.53
5. Step 5: Solve for x
   x = 1,173,914.53/1,219.32
6. Step 6: Final answer
   x = 962.76