Home / 326.25-489.21-120.78

Finding the Fourth Proportional to 326.25, 489.21 and 120.78

Calculator

Solution

The fourth proportional to 326.25, 489.21 and 120.78 is: 181.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    326.25 : 489.21 = 120.78 : x
  2. Step 2: Convert to fraction form
    326.25/489.21 = 120.78/x
  3. Step 3: Cross multiply
    326.25x = 489.21 × 120.78
  4. Step 4: Simplify right side
    326.25x = 59,086.78
  5. Step 5: Solve for x
    x = 59,086.78/326.25
  6. Step 6: Final answer
    x = 181.11

Related Problems

Find fourth proportional to 163.13, 244.61 and 60.39
Half scale
Find fourth proportional to 652.50, 978.42 and 241.56
Double scale
Find fourth proportional to 327.25, 490.71 and 121.78
Similar ratio
Find fourth proportional to 489.38, 733.82 and 181.17
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.