Home / 260-390-108

Finding the Fourth Proportional to 260, 390 and 108

Calculator

Solution

The fourth proportional to 260, 390 and 108 is: 162

Step by Step Solution

  1. Step 1: Write the proportion equation
    260 : 390 = 108 : x
  2. Step 2: Convert to fraction form
    260/390 = 108/x
  3. Step 3: Cross multiply
    260x = 390 × 108
  4. Step 4: Simplify right side
    260x = 42,120
  5. Step 5: Solve for x
    x = 42,120/260
  6. Step 6: Final answer
    x = 162

Related Problems

Find fourth proportional to 130, 195 and 54
Half scale
Find fourth proportional to 520, 780 and 216
Double scale
Find fourth proportional to 261, 391.50 and 109
Similar ratio
Find fourth proportional to 390, 585 and 162
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.