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Finding the Fourth Proportional to 266.28, 399.27 and 81.15

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Solution

The fourth proportional to 266.28, 399.27 and 81.15 is: 121.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    266.28 : 399.27 = 81.15 : x
  2. Step 2: Convert to fraction form
    266.28/399.27 = 81.15/x
  3. Step 3: Cross multiply
    266.28x = 399.27 × 81.15
  4. Step 4: Simplify right side
    266.28x = 32,400.76
  5. Step 5: Solve for x
    x = 32,400.76/266.28
  6. Step 6: Final answer
    x = 121.68

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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.