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Finding the Fourth Proportional to 394.40, 542.64 and 385.19

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Solution

The fourth proportional to 394.40, 542.64 and 385.19 is: 529.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    394.40 : 542.64 = 385.19 : x
  2. Step 2: Convert to fraction form
    394.40/542.64 = 385.19/x
  3. Step 3: Cross multiply
    394.40x = 542.64 × 385.19
  4. Step 4: Simplify right side
    394.40x = 209,016.79
  5. Step 5: Solve for x
    x = 209,016.79/394.40
  6. Step 6: Final answer
    x = 529.97

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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.