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Finding the Fourth Proportional to 430.43, 645.89 and 257.51

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Solution

The fourth proportional to 430.43, 645.89 and 257.51 is: 386.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.43 : 645.89 = 257.51 : x
  2. Step 2: Convert to fraction form
    430.43/645.89 = 257.51/x
  3. Step 3: Cross multiply
    430.43x = 645.89 × 257.51
  4. Step 4: Simplify right side
    430.43x = 166,323.46
  5. Step 5: Solve for x
    x = 166,323.46/430.43
  6. Step 6: Final answer
    x = 386.42

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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.