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Finding the Fourth Proportional to 645.76, 968.56 and 212.80

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Solution

The fourth proportional to 645.76, 968.56 and 212.80 is: 319.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.76 : 968.56 = 212.80 : x
  2. Step 2: Convert to fraction form
    645.76/968.56 = 212.80/x
  3. Step 3: Cross multiply
    645.76x = 968.56 × 212.80
  4. Step 4: Simplify right side
    645.76x = 206,109.57
  5. Step 5: Solve for x
    x = 206,109.57/645.76
  6. Step 6: Final answer
    x = 319.17

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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.