Finding the Fourth Proportional to 1,685.61, 2,526.69 and 645.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,685.61 : 2,526.69 = 645.33 : x
2. Step 2: Convert to fraction form
   1,685.61/2,526.69 = 645.33/x
3. Step 3: Cross multiply
   1,685.61x = 2,526.69 × 645.33
4. Step 4: Simplify right side
   1,685.61x = 1,630,548.86
5. Step 5: Solve for x
   x = 1,630,548.86/1,685.61
6. Step 6: Final answer
   x = 967.33