Finding the Fourth Proportional to 3,870.78, 5,802.61 and 1,405.01

Step by Step Solution

1. Step 1: Write the proportion equation
   3,870.78 : 5,802.61 = 1,405.01 : x
2. Step 2: Convert to fraction form
   3,870.78/5,802.61 = 1,405.01/x
3. Step 3: Cross multiply
   3,870.78x = 5,802.61 × 1,405.01
4. Step 4: Simplify right side
   3,870.78x = 8,152,725.08
5. Step 5: Solve for x
   x = 8,152,725.08/3,870.78
6. Step 6: Final answer
   x = 2,106.22