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Finding the Fourth Proportional to 486.72, 729.60 and 212.88

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Solution

The fourth proportional to 486.72, 729.60 and 212.88 is: 319.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.72 : 729.60 = 212.88 : x
  2. Step 2: Convert to fraction form
    486.72/729.60 = 212.88/x
  3. Step 3: Cross multiply
    486.72x = 729.60 × 212.88
  4. Step 4: Simplify right side
    486.72x = 155,317.25
  5. Step 5: Solve for x
    x = 155,317.25/486.72
  6. Step 6: Final answer
    x = 319.11

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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.