Home / 819.87-1,230-272.06

Finding the Fourth Proportional to 819.87, 1,230 and 272.06

Calculator

Solution

The fourth proportional to 819.87, 1,230 and 272.06 is: 408.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.87 : 1,230 = 272.06 : x
  2. Step 2: Convert to fraction form
    819.87/1,230 = 272.06/x
  3. Step 3: Cross multiply
    819.87x = 1,230 × 272.06
  4. Step 4: Simplify right side
    819.87x = 334,633.80
  5. Step 5: Solve for x
    x = 334,633.80/819.87
  6. Step 6: Final answer
    x = 408.15

Related Problems

Find fourth proportional to 409.94, 615 and 136.03
Half scale
Find fourth proportional to 1,639.74, 2,460 and 544.12
Double scale
Find fourth proportional to 820.87, 1,231.50 and 273.06
Similar ratio
Find fourth proportional to 1,229.81, 1,845 and 408.09
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.