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Finding the Fourth Proportional to 645.39, 964.38 and 438.23

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Solution

The fourth proportional to 645.39, 964.38 and 438.23 is: 654.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.39 : 964.38 = 438.23 : x
  2. Step 2: Convert to fraction form
    645.39/964.38 = 438.23/x
  3. Step 3: Cross multiply
    645.39x = 964.38 × 438.23
  4. Step 4: Simplify right side
    645.39x = 422,615.43
  5. Step 5: Solve for x
    x = 422,615.43/645.39
  6. Step 6: Final answer
    x = 654.82

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.