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Finding the Fourth Proportional to 419.64, 628.81 and 213.90

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Solution

The fourth proportional to 419.64, 628.81 and 213.90 is: 320.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.64 : 628.81 = 213.90 : x
  2. Step 2: Convert to fraction form
    419.64/628.81 = 213.90/x
  3. Step 3: Cross multiply
    419.64x = 628.81 × 213.90
  4. Step 4: Simplify right side
    419.64x = 134,502.46
  5. Step 5: Solve for x
    x = 134,502.46/419.64
  6. Step 6: Final answer
    x = 320.52

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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.