Finding the Fourth Proportional to 13,021.42, 17,971.86 and 7,719.16

Step by Step Solution

1. Step 1: Write the proportion equation
   13,021.42 : 17,971.86 = 7,719.16 : x
2. Step 2: Convert to fraction form
   13,021.42/17,971.86 = 7,719.16/x
3. Step 3: Cross multiply
   13,021.42x = 17,971.86 × 7,719.16
4. Step 4: Simplify right side
   13,021.42x = 138,727,662.84
5. Step 5: Solve for x
   x = 138,727,662.84/13,021.42
6. Step 6: Final answer
   x = 10,653.80