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Finding the Fourth Proportional to 429.72, 644.58 and 386.79

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Solution

The fourth proportional to 429.72, 644.58 and 386.79 is: 580.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.72 : 644.58 = 386.79 : x
  2. Step 2: Convert to fraction form
    429.72/644.58 = 386.79/x
  3. Step 3: Cross multiply
    429.72x = 644.58 × 386.79
  4. Step 4: Simplify right side
    429.72x = 249,317.10
  5. Step 5: Solve for x
    x = 249,317.10/429.72
  6. Step 6: Final answer
    x = 580.19

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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.