Home / 487.20-672.38-290.69

Finding the Fourth Proportional to 487.20, 672.38 and 290.69

Calculator

Solution

The fourth proportional to 487.20, 672.38 and 290.69 is: 401.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    487.20 : 672.38 = 290.69 : x
  2. Step 2: Convert to fraction form
    487.20/672.38 = 290.69/x
  3. Step 3: Cross multiply
    487.20x = 672.38 × 290.69
  4. Step 4: Simplify right side
    487.20x = 195,449.33
  5. Step 5: Solve for x
    x = 195,449.33/487.20
  6. Step 6: Final answer
    x = 401.17

Related Problems

Find fourth proportional to 243.60, 336.19 and 145.34
Half scale
Find fourth proportional to 974.40, 1,344.75 and 581.37
Double scale
Find fourth proportional to 488.20, 673.76 and 291.69
Similar ratio
Find fourth proportional to 730.80, 1,008.56 and 436.03
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.