Finding the Fourth Proportional to 1,398.90, 1,931.28 and 974.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.90 : 1,931.28 = 974.15 : x
2. Step 2: Convert to fraction form
   1,398.90/1,931.28 = 974.15/x
3. Step 3: Cross multiply
   1,398.90x = 1,931.28 × 974.15
4. Step 4: Simplify right side
   1,398.90x = 1,881,346.76
5. Step 5: Solve for x
   x = 1,881,346.76/1,398.90
6. Step 6: Final answer
   x = 1,344.88