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Finding the Fourth Proportional to 645.17, 967.21 and 428.63

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Solution

The fourth proportional to 645.17, 967.21 and 428.63 is: 642.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.17 : 967.21 = 428.63 : x
  2. Step 2: Convert to fraction form
    645.17/967.21 = 428.63/x
  3. Step 3: Cross multiply
    645.17x = 967.21 × 428.63
  4. Step 4: Simplify right side
    645.17x = 414,569.31
  5. Step 5: Solve for x
    x = 414,569.31/645.17
  6. Step 6: Final answer
    x = 642.58

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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.