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Finding the Fourth Proportional to 645.98, 969.42 and 280.86

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Solution

The fourth proportional to 645.98, 969.42 and 280.86 is: 421.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.98 : 969.42 = 280.86 : x
  2. Step 2: Convert to fraction form
    645.98/969.42 = 280.86/x
  3. Step 3: Cross multiply
    645.98x = 969.42 × 280.86
  4. Step 4: Simplify right side
    645.98x = 272,271.30
  5. Step 5: Solve for x
    x = 272,271.30/645.98
  6. Step 6: Final answer
    x = 421.49

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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.