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Finding the Fourth Proportional to 430.25, 645.39 and 137.75

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Solution

The fourth proportional to 430.25, 645.39 and 137.75 is: 206.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.25 : 645.39 = 137.75 : x
  2. Step 2: Convert to fraction form
    430.25/645.39 = 137.75/x
  3. Step 3: Cross multiply
    430.25x = 645.39 × 137.75
  4. Step 4: Simplify right side
    430.25x = 88,902.47
  5. Step 5: Solve for x
    x = 88,902.47/430.25
  6. Step 6: Final answer
    x = 206.63

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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.