Finding the Fourth Proportional to 1,870.31, 2,806.09 and 571.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,870.31 : 2,806.09 = 571.79 : x
2. Step 2: Convert to fraction form
   1,870.31/2,806.09 = 571.79/x
3. Step 3: Cross multiply
   1,870.31x = 2,806.09 × 571.79
4. Step 4: Simplify right side
   1,870.31x = 1,604,499.79
5. Step 5: Solve for x
   x = 1,604,499.79/1,870.31
6. Step 6: Final answer
   x = 857.88