Home / 1,211.86-1,818-389.92

Finding the Fourth Proportional to 1,211.86, 1,818 and 389.92

Calculator

Solution

The fourth proportional to 1,211.86, 1,818 and 389.92 is: 584.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,211.86 : 1,818 = 389.92 : x
  2. Step 2: Convert to fraction form
    1,211.86/1,818 = 389.92/x
  3. Step 3: Cross multiply
    1,211.86x = 1,818 × 389.92
  4. Step 4: Simplify right side
    1,211.86x = 708,874.56
  5. Step 5: Solve for x
    x = 708,874.56/1,211.86
  6. Step 6: Final answer
    x = 584.95

Related Problems

Find fourth proportional to 605.93, 909 and 194.96
Half scale
Find fourth proportional to 2,423.72, 3,636 and 779.84
Double scale
Find fourth proportional to 1,212.86, 1,819.50 and 390.92
Similar ratio
Find fourth proportional to 1,817.79, 2,727 and 584.88
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.