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Finding the Fourth Proportional to 642.76, 963.66 and 386.44

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Solution

The fourth proportional to 642.76, 963.66 and 386.44 is: 579.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.76 : 963.66 = 386.44 : x
  2. Step 2: Convert to fraction form
    642.76/963.66 = 386.44/x
  3. Step 3: Cross multiply
    642.76x = 963.66 × 386.44
  4. Step 4: Simplify right side
    642.76x = 372,396.77
  5. Step 5: Solve for x
    x = 372,396.77/642.76
  6. Step 6: Final answer
    x = 579.37

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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.