Home / 909.81-1,365.39-389.79

Finding the Fourth Proportional to 909.81, 1,365.39 and 389.79

Calculator

Solution

The fourth proportional to 909.81, 1,365.39 and 389.79 is: 584.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    909.81 : 1,365.39 = 389.79 : x
  2. Step 2: Convert to fraction form
    909.81/1,365.39 = 389.79/x
  3. Step 3: Cross multiply
    909.81x = 1,365.39 × 389.79
  4. Step 4: Simplify right side
    909.81x = 532,215.37
  5. Step 5: Solve for x
    x = 532,215.37/909.81
  6. Step 6: Final answer
    x = 584.97

Related Problems

Find fourth proportional to 454.91, 682.70 and 194.90
Half scale
Find fourth proportional to 1,819.62, 2,730.78 and 779.58
Double scale
Find fourth proportional to 910.81, 1,366.89 and 390.79
Similar ratio
Find fourth proportional to 1,364.72, 2,048.09 and 584.69
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.