Finding the Fourth Proportional to 1,408.72, 2,112.86 and 887.13

Step by Step Solution

1. Step 1: Write the proportion equation
   1,408.72 : 2,112.86 = 887.13 : x
2. Step 2: Convert to fraction form
   1,408.72/2,112.86 = 887.13/x
3. Step 3: Cross multiply
   1,408.72x = 2,112.86 × 887.13
4. Step 4: Simplify right side
   1,408.72x = 1,874,381.49
5. Step 5: Solve for x
   x = 1,874,381.49/1,408.72
6. Step 6: Final answer
   x = 1,330.56