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Finding the Fourth Proportional to 430.73, 645.64 and 257.45

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Solution

The fourth proportional to 430.73, 645.64 and 257.45 is: 385.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.73 : 645.64 = 257.45 : x
  2. Step 2: Convert to fraction form
    430.73/645.64 = 257.45/x
  3. Step 3: Cross multiply
    430.73x = 645.64 × 257.45
  4. Step 4: Simplify right side
    430.73x = 166,216.15
  5. Step 5: Solve for x
    x = 166,216.15/430.73
  6. Step 6: Final answer
    x = 385.89

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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.