Finding the Fourth Proportional to 21,870.84, 32,804.40 and 13,099.32

Step by Step Solution

1. Step 1: Write the proportion equation
   21,870.84 : 32,804.40 = 13,099.32 : x
2. Step 2: Convert to fraction form
   21,870.84/32,804.40 = 13,099.32/x
3. Step 3: Cross multiply
   21,870.84x = 32,804.40 × 13,099.32
4. Step 4: Simplify right side
   21,870.84x = 429,715,333.01
5. Step 5: Solve for x
   x = 429,715,333.01/21,870.84
6. Step 6: Final answer
   x = 19,647.87