Finding the Fourth Proportional to 1,397.45, 1,927.99 and 830.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.45 : 1,927.99 = 830.15 : x
2. Step 2: Convert to fraction form
   1,397.45/1,927.99 = 830.15/x
3. Step 3: Cross multiply
   1,397.45x = 1,927.99 × 830.15
4. Step 4: Simplify right side
   1,397.45x = 1,600,509.18
5. Step 5: Solve for x
   x = 1,600,509.18/1,397.45
6. Step 6: Final answer
   x = 1,145.30