Finding the Fourth Proportional to 1,111.26, 1,533.56 and 645.51

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.26 : 1,533.56 = 645.51 : x
2. Step 2: Convert to fraction form
   1,111.26/1,533.56 = 645.51/x
3. Step 3: Cross multiply
   1,111.26x = 1,533.56 × 645.51
4. Step 4: Simplify right side
   1,111.26x = 989,925.09
5. Step 5: Solve for x
   x = 989,925.09/1,111.26
6. Step 6: Final answer
   x = 890.81