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Finding the Fourth Proportional to 429.53, 643.55 and 386.73

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Solution

The fourth proportional to 429.53, 643.55 and 386.73 is: 579.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.53 : 643.55 = 386.73 : x
  2. Step 2: Convert to fraction form
    429.53/643.55 = 386.73/x
  3. Step 3: Cross multiply
    429.53x = 643.55 × 386.73
  4. Step 4: Simplify right side
    429.53x = 248,878.16
  5. Step 5: Solve for x
    x = 248,878.16/429.53
  6. Step 6: Final answer
    x = 579.43

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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.