Home / 538.39-807.72-213.85

Finding the Fourth Proportional to 538.39, 807.72 and 213.85

Calculator

Solution

The fourth proportional to 538.39, 807.72 and 213.85 is: 320.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    538.39 : 807.72 = 213.85 : x
  2. Step 2: Convert to fraction form
    538.39/807.72 = 213.85/x
  3. Step 3: Cross multiply
    538.39x = 807.72 × 213.85
  4. Step 4: Simplify right side
    538.39x = 172,730.92
  5. Step 5: Solve for x
    x = 172,730.92/538.39
  6. Step 6: Final answer
    x = 320.83

Related Problems

Find fourth proportional to 269.20, 403.86 and 106.93
Half scale
Find fourth proportional to 1,076.78, 1,615.44 and 427.70
Double scale
Find fourth proportional to 539.39, 809.22 and 214.85
Similar ratio
Find fourth proportional to 807.59, 1,211.58 and 320.78
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.