Finding the Fourth Proportional to 78.83, 108.74 and 65.07

Step by Step Solution

1. Step 1: Write the proportion equation
   78.83 : 108.74 = 65.07 : x
2. Step 2: Convert to fraction form
   78.83/108.74 = 65.07/x
3. Step 3: Cross multiply
   78.83x = 108.74 × 65.07
4. Step 4: Simplify right side
   78.83x = 7,075.71
5. Step 5: Solve for x
   x = 7,075.71/78.83
6. Step 6: Final answer
   x = 89.76