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Finding the Fourth Proportional to 645.82, 968.91 and 213.28

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Solution

The fourth proportional to 645.82, 968.91 and 213.28 is: 319.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.82 : 968.91 = 213.28 : x
  2. Step 2: Convert to fraction form
    645.82/968.91 = 213.28/x
  3. Step 3: Cross multiply
    645.82x = 968.91 × 213.28
  4. Step 4: Simplify right side
    645.82x = 206,649.12
  5. Step 5: Solve for x
    x = 206,649.12/645.82
  6. Step 6: Final answer
    x = 319.98

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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.