Finding the Fourth Proportional to 13,978.56, 19,290.82 and 7,690.94

Step by Step Solution

1. Step 1: Write the proportion equation
   13,978.56 : 19,290.82 = 7,690.94 : x
2. Step 2: Convert to fraction form
   13,978.56/19,290.82 = 7,690.94/x
3. Step 3: Cross multiply
   13,978.56x = 19,290.82 × 7,690.94
4. Step 4: Simplify right side
   13,978.56x = 148,364,539.17
5. Step 5: Solve for x
   x = 148,364,539.17/13,978.56
6. Step 6: Final answer
   x = 10,613.72