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Finding the Fourth Proportional to 456.38, 684.64 and 212.88

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Solution

The fourth proportional to 456.38, 684.64 and 212.88 is: 319.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    456.38 : 684.64 = 212.88 : x
  2. Step 2: Convert to fraction form
    456.38/684.64 = 212.88/x
  3. Step 3: Cross multiply
    456.38x = 684.64 × 212.88
  4. Step 4: Simplify right side
    456.38x = 145,746.16
  5. Step 5: Solve for x
    x = 145,746.16/456.38
  6. Step 6: Final answer
    x = 319.35

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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.