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Finding the Fourth Proportional to 430.09, 644.81 and 221.33

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Solution

The fourth proportional to 430.09, 644.81 and 221.33 is: 331.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.09 : 644.81 = 221.33 : x
  2. Step 2: Convert to fraction form
    430.09/644.81 = 221.33/x
  3. Step 3: Cross multiply
    430.09x = 644.81 × 221.33
  4. Step 4: Simplify right side
    430.09x = 142,711.47
  5. Step 5: Solve for x
    x = 142,711.47/430.09
  6. Step 6: Final answer
    x = 331.82

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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.