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Finding the Fourth Proportional to 220.69, 330.90 and 139.51

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Solution

The fourth proportional to 220.69, 330.90 and 139.51 is: 209.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    220.69 : 330.90 = 139.51 : x
  2. Step 2: Convert to fraction form
    220.69/330.90 = 139.51/x
  3. Step 3: Cross multiply
    220.69x = 330.90 × 139.51
  4. Step 4: Simplify right side
    220.69x = 46,163.86
  5. Step 5: Solve for x
    x = 46,163.86/220.69
  6. Step 6: Final answer
    x = 209.18

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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.