Finding the Fourth Proportional to 13,978.08, 19,290.69 and 7,690.86

Step by Step Solution

1. Step 1: Write the proportion equation
   13,978.08 : 19,290.69 = 7,690.86 : x
2. Step 2: Convert to fraction form
   13,978.08/19,290.69 = 7,690.86/x
3. Step 3: Cross multiply
   13,978.08x = 19,290.69 × 7,690.86
4. Step 4: Simplify right side
   13,978.08x = 148,361,996.09
5. Step 5: Solve for x
   x = 148,361,996.09/13,978.08
6. Step 6: Final answer
   x = 10,613.90