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Finding the Fourth Proportional to 430.24, 645.81 and 257.11

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Solution

The fourth proportional to 430.24, 645.81 and 257.11 is: 385.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.24 : 645.81 = 257.11 : x
  2. Step 2: Convert to fraction form
    430.24/645.81 = 257.11/x
  3. Step 3: Cross multiply
    430.24x = 645.81 × 257.11
  4. Step 4: Simplify right side
    430.24x = 166,044.21
  5. Step 5: Solve for x
    x = 166,044.21/430.24
  6. Step 6: Final answer
    x = 385.93

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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.