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Finding the Fourth Proportional to 486.81, 729.79 and 212.69

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Solution

The fourth proportional to 486.81, 729.79 and 212.69 is: 318.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.81 : 729.79 = 212.69 : x
  2. Step 2: Convert to fraction form
    486.81/729.79 = 212.69/x
  3. Step 3: Cross multiply
    486.81x = 729.79 × 212.69
  4. Step 4: Simplify right side
    486.81x = 155,219.04
  5. Step 5: Solve for x
    x = 155,219.04/486.81
  6. Step 6: Final answer
    x = 318.85

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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.