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Finding the Fourth Proportional to 645.45, 967.85 and 212.55

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Solution

The fourth proportional to 645.45, 967.85 and 212.55 is: 318.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.45 : 967.85 = 212.55 : x
  2. Step 2: Convert to fraction form
    645.45/967.85 = 212.55/x
  3. Step 3: Cross multiply
    645.45x = 967.85 × 212.55
  4. Step 4: Simplify right side
    645.45x = 205,715.45
  5. Step 5: Solve for x
    x = 205,715.45/645.45
  6. Step 6: Final answer
    x = 318.72

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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.