Finding the Fourth Proportional to 1,111.50, 1,533.96 and 645.84

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.50 : 1,533.96 = 645.84 : x
2. Step 2: Convert to fraction form
   1,111.50/1,533.96 = 645.84/x
3. Step 3: Cross multiply
   1,111.50x = 1,533.96 × 645.84
4. Step 4: Simplify right side
   1,111.50x = 990,692.73
5. Step 5: Solve for x
   x = 990,692.73/1,111.50
6. Step 6: Final answer
   x = 891.31