Finding the Fourth Proportional to 916.72, 1,372.49 and 830.23

Step by Step Solution

1. Step 1: Write the proportion equation
   916.72 : 1,372.49 = 830.23 : x
2. Step 2: Convert to fraction form
   916.72/1,372.49 = 830.23/x
3. Step 3: Cross multiply
   916.72x = 1,372.49 × 830.23
4. Step 4: Simplify right side
   916.72x = 1,139,478.22
5. Step 5: Solve for x
   x = 1,139,478.22/916.72
6. Step 6: Final answer
   x = 1,242.99