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Finding the Fourth Proportional to 280.96, 420.66 and 212.28

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Solution

The fourth proportional to 280.96, 420.66 and 212.28 is: 317.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.96 : 420.66 = 212.28 : x
  2. Step 2: Convert to fraction form
    280.96/420.66 = 212.28/x
  3. Step 3: Cross multiply
    280.96x = 420.66 × 212.28
  4. Step 4: Simplify right side
    280.96x = 89,297.70
  5. Step 5: Solve for x
    x = 89,297.70/280.96
  6. Step 6: Final answer
    x = 317.83

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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.