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Finding the Fourth Proportional to 285.92, 394.40 and 215.76

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Solution

The fourth proportional to 285.92, 394.40 and 215.76 is: 297.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.92 : 394.40 = 215.76 : x
  2. Step 2: Convert to fraction form
    285.92/394.40 = 215.76/x
  3. Step 3: Cross multiply
    285.92x = 394.40 × 215.76
  4. Step 4: Simplify right side
    285.92x = 85,095.74
  5. Step 5: Solve for x
    x = 85,095.74/285.92
  6. Step 6: Final answer
    x = 297.62

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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.