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Finding the Fourth Proportional to 430.38, 643.97 and 257.14

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Solution

The fourth proportional to 430.38, 643.97 and 257.14 is: 384.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.38 : 643.97 = 257.14 : x
  2. Step 2: Convert to fraction form
    430.38/643.97 = 257.14/x
  3. Step 3: Cross multiply
    430.38x = 643.97 × 257.14
  4. Step 4: Simplify right side
    430.38x = 165,590.45
  5. Step 5: Solve for x
    x = 165,590.45/430.38
  6. Step 6: Final answer
    x = 384.75

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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.