Finding the Fourth Proportional to 1,019.00, 1,406.23 and 645.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.00 : 1,406.23 = 645.59 : x
2. Step 2: Convert to fraction form
   1,019.00/1,406.23 = 645.59/x
3. Step 3: Cross multiply
   1,019.00x = 1,406.23 × 645.59
4. Step 4: Simplify right side
   1,019.00x = 907,849.93
5. Step 5: Solve for x
   x = 907,849.93/1,019.00
6. Step 6: Final answer
   x = 890.92