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Finding the Fourth Proportional to 266.72, 399.36 and 212.80

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Solution

The fourth proportional to 266.72, 399.36 and 212.80 is: 318.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    266.72 : 399.36 = 212.80 : x
  2. Step 2: Convert to fraction form
    266.72/399.36 = 212.80/x
  3. Step 3: Cross multiply
    266.72x = 399.36 × 212.80
  4. Step 4: Simplify right side
    266.72x = 84,983.81
  5. Step 5: Solve for x
    x = 84,983.81/266.72
  6. Step 6: Final answer
    x = 318.63

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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.