Finding the Fourth Proportional to 1,428.33, 1,971.03 and 830.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.33 : 1,971.03 = 830.76 : x
2. Step 2: Convert to fraction form
   1,428.33/1,971.03 = 830.76/x
3. Step 3: Cross multiply
   1,428.33x = 1,971.03 × 830.76
4. Step 4: Simplify right side
   1,428.33x = 1,637,448.61
5. Step 5: Solve for x
   x = 1,637,448.61/1,428.33
6. Step 6: Final answer
   x = 1,146.40