Finding the Fourth Proportional to 1,913.98, 2,870.86 and 939.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,913.98 : 2,870.86 = 939.76 : x
2. Step 2: Convert to fraction form
   1,913.98/2,870.86 = 939.76/x
3. Step 3: Cross multiply
   1,913.98x = 2,870.86 × 939.76
4. Step 4: Simplify right side
   1,913.98x = 2,697,919.39
5. Step 5: Solve for x
   x = 2,697,919.39/1,913.98
6. Step 6: Final answer
   x = 1,409.59