Finding the Fourth Proportional to 2,648.78, 3,971.63 and 893.21

Step by Step Solution

1. Step 1: Write the proportion equation
   2,648.78 : 3,971.63 = 893.21 : x
2. Step 2: Convert to fraction form
   2,648.78/3,971.63 = 893.21/x
3. Step 3: Cross multiply
   2,648.78x = 3,971.63 × 893.21
4. Step 4: Simplify right side
   2,648.78x = 3,547,499.32
5. Step 5: Solve for x
   x = 3,547,499.32/2,648.78
6. Step 6: Final answer
   x = 1,339.29