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Finding the Fourth Proportional to 390.72, 539.61 and 266.73

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Solution

The fourth proportional to 390.72, 539.61 and 266.73 is: 368.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.72 : 539.61 = 266.73 : x
  2. Step 2: Convert to fraction form
    390.72/539.61 = 266.73/x
  3. Step 3: Cross multiply
    390.72x = 539.61 × 266.73
  4. Step 4: Simplify right side
    390.72x = 143,930.18
  5. Step 5: Solve for x
    x = 143,930.18/390.72
  6. Step 6: Final answer
    x = 368.37

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.