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Finding the Fourth Proportional to 430.28, 645.04 and 210.78

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Solution

The fourth proportional to 430.28, 645.04 and 210.78 is: 315.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.28 : 645.04 = 210.78 : x
  2. Step 2: Convert to fraction form
    430.28/645.04 = 210.78/x
  3. Step 3: Cross multiply
    430.28x = 645.04 × 210.78
  4. Step 4: Simplify right side
    430.28x = 135,962.62
  5. Step 5: Solve for x
    x = 135,962.62/430.28
  6. Step 6: Final answer
    x = 315.98

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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.