Finding the Fourth Proportional to 1,021.61, 1,531.51 and 849.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,021.61 : 1,531.51 = 849.69 : x
2. Step 2: Convert to fraction form
   1,021.61/1,531.51 = 849.69/x
3. Step 3: Cross multiply
   1,021.61x = 1,531.51 × 849.69
4. Step 4: Simplify right side
   1,021.61x = 1,301,306.61
5. Step 5: Solve for x
   x = 1,301,306.61/1,021.61
6. Step 6: Final answer
   x = 1,273.78