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Finding the Fourth Proportional to 429.85, 642.35 and 320.41

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Solution

The fourth proportional to 429.85, 642.35 and 320.41 is: 478.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.85 : 642.35 = 320.41 : x
  2. Step 2: Convert to fraction form
    429.85/642.35 = 320.41/x
  3. Step 3: Cross multiply
    429.85x = 642.35 × 320.41
  4. Step 4: Simplify right side
    429.85x = 205,815.36
  5. Step 5: Solve for x
    x = 205,815.36/429.85
  6. Step 6: Final answer
    x = 478.81

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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.