Finding the Fourth Proportional to 2,646.32, 3,969.50 and 891

Step by Step Solution

1. Step 1: Write the proportion equation
   2,646.32 : 3,969.50 = 891 : x
2. Step 2: Convert to fraction form
   2,646.32/3,969.50 = 891/x
3. Step 3: Cross multiply
   2,646.32x = 3,969.50 × 891
4. Step 4: Simplify right side
   2,646.32x = 3,536,824.50
5. Step 5: Solve for x
   x = 3,536,824.50/2,646.32
6. Step 6: Final answer
   x = 1,336.51