Home / 324.67-487-81.20

Finding the Fourth Proportional to 324.67, 487 and 81.20

Calculator

Solution

The fourth proportional to 324.67, 487 and 81.20 is: 121.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    324.67 : 487 = 81.20 : x
  2. Step 2: Convert to fraction form
    324.67/487 = 81.20/x
  3. Step 3: Cross multiply
    324.67x = 487 × 81.20
  4. Step 4: Simplify right side
    324.67x = 39,544.40
  5. Step 5: Solve for x
    x = 39,544.40/324.67
  6. Step 6: Final answer
    x = 121.80

Related Problems

Find fourth proportional to 162.34, 243.50 and 40.60
Half scale
Find fourth proportional to 649.34, 974 and 162.40
Double scale
Find fourth proportional to 325.67, 488.50 and 82.20
Similar ratio
Find fourth proportional to 487.01, 730.50 and 121.80
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.