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Finding the Fourth Proportional to 394.78, 545.22 and 307.31

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Solution

The fourth proportional to 394.78, 545.22 and 307.31 is: 424.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    394.78 : 545.22 = 307.31 : x
  2. Step 2: Convert to fraction form
    394.78/545.22 = 307.31/x
  3. Step 3: Cross multiply
    394.78x = 545.22 × 307.31
  4. Step 4: Simplify right side
    394.78x = 167,552.92
  5. Step 5: Solve for x
    x = 167,552.92/394.78
  6. Step 6: Final answer
    x = 424.42

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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.