Home / 379.39-569.09-209.47

Finding the Fourth Proportional to 379.39, 569.09 and 209.47

Calculator

Solution

The fourth proportional to 379.39, 569.09 and 209.47 is: 314.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    379.39 : 569.09 = 209.47 : x
  2. Step 2: Convert to fraction form
    379.39/569.09 = 209.47/x
  3. Step 3: Cross multiply
    379.39x = 569.09 × 209.47
  4. Step 4: Simplify right side
    379.39x = 119,206.23
  5. Step 5: Solve for x
    x = 119,206.23/379.39
  6. Step 6: Final answer
    x = 314.21

Related Problems

Find fourth proportional to 189.70, 284.54 and 104.74
Half scale
Find fourth proportional to 758.78, 1,138.17 and 418.94
Double scale
Find fourth proportional to 380.39, 570.59 and 210.47
Similar ratio
Find fourth proportional to 569.09, 853.63 and 314.21
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.