Finding the Fourth Proportional to 1,915.42, 2,642.82 and 1,216.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,915.42 : 2,642.82 = 1,216.39 : x
2. Step 2: Convert to fraction form
   1,915.42/2,642.82 = 1,216.39/x
3. Step 3: Cross multiply
   1,915.42x = 2,642.82 × 1,216.39
4. Step 4: Simplify right side
   1,915.42x = 3,214,699.82
5. Step 5: Solve for x
   x = 3,214,699.82/1,915.42
6. Step 6: Final answer
   x = 1,678.33