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Finding the Fourth Proportional to 642.78, 964.64 and 437.56

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Solution

The fourth proportional to 642.78, 964.64 and 437.56 is: 656.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.78 : 964.64 = 437.56 : x
  2. Step 2: Convert to fraction form
    642.78/964.64 = 437.56/x
  3. Step 3: Cross multiply
    642.78x = 964.64 × 437.56
  4. Step 4: Simplify right side
    642.78x = 422,087.88
  5. Step 5: Solve for x
    x = 422,087.88/642.78
  6. Step 6: Final answer
    x = 656.66

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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.