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Finding the Fourth Proportional to 285.68, 393.86 and 215.82

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Solution

The fourth proportional to 285.68, 393.86 and 215.82 is: 297.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.68 : 393.86 = 215.82 : x
  2. Step 2: Convert to fraction form
    285.68/393.86 = 215.82/x
  3. Step 3: Cross multiply
    285.68x = 393.86 × 215.82
  4. Step 4: Simplify right side
    285.68x = 85,002.87
  5. Step 5: Solve for x
    x = 85,002.87/285.68
  6. Step 6: Final answer
    x = 297.55

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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.