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Finding the Fourth Proportional to 390.78, 539.24 and 222.73

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Solution

The fourth proportional to 390.78, 539.24 and 222.73 is: 307.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.78 : 539.24 = 222.73 : x
  2. Step 2: Convert to fraction form
    390.78/539.24 = 222.73/x
  3. Step 3: Cross multiply
    390.78x = 539.24 × 222.73
  4. Step 4: Simplify right side
    390.78x = 120,104.93
  5. Step 5: Solve for x
    x = 120,104.93/390.78
  6. Step 6: Final answer
    x = 307.35

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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.