Finding the Fourth Proportional to 1,221.42, 1,685.82 and 974.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,221.42 : 1,685.82 = 974.69 : x
2. Step 2: Convert to fraction form
   1,221.42/1,685.82 = 974.69/x
3. Step 3: Cross multiply
   1,221.42x = 1,685.82 × 974.69
4. Step 4: Simplify right side
   1,221.42x = 1,643,151.90
5. Step 5: Solve for x
   x = 1,643,151.90/1,221.42
6. Step 6: Final answer
   x = 1,345.28