Finding the Fourth Proportional to 10,870.77, 16,300.65 and 5,315.79

Step by Step Solution

1. Step 1: Write the proportion equation
   10,870.77 : 16,300.65 = 5,315.79 : x
2. Step 2: Convert to fraction form
   10,870.77/16,300.65 = 5,315.79/x
3. Step 3: Cross multiply
   10,870.77x = 16,300.65 × 5,315.79
4. Step 4: Simplify right side
   10,870.77x = 86,650,832.26
5. Step 5: Solve for x
   x = 86,650,832.26/10,870.77
6. Step 6: Final answer
   x = 7,970.99