Finding the Fourth Proportional to 1,430.30, 1,973.84 and 870.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,430.30 : 1,973.84 = 870.78 : x
2. Step 2: Convert to fraction form
   1,430.30/1,973.84 = 870.78/x
3. Step 3: Cross multiply
   1,430.30x = 1,973.84 × 870.78
4. Step 4: Simplify right side
   1,430.30x = 1,718,780.40
5. Step 5: Solve for x
   x = 1,718,780.40/1,430.30
6. Step 6: Final answer
   x = 1,201.69